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THE  LIBRARY 

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THE  UNIVERSITY 

OF  CALIFORNIA 


PRESENTED  BY 

PROF.  CHARLES  A.  KOFOID  AND 

MRS.  PRUDENCE  W.  KOFOID 


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ON    THE 

GEOGRAPHICAL     DISTRIBUTION 

OF 

TROPICAL  DISEASES  IN  AFRICA 


ON  THE 

GEOGRAPHICAL    DISTRIBUTION 


OF 


TROPICAL  DISEASES  IN  AFRICA 


WITH  AN  APPENDIX 

ON  A  NEW  METHOD  OF  ILLUSTRATING 
THE  GEOGRAPHICAL  DISTRIBUTION  OF  DISEASE 


BY 

R.  W.  FELKIN,  M.D.,  F.R.S.E.,  F.R.G.S. 

LECTURER  ON    TROPICAL   DISEASES    AND   CLIMATOLOGY, 
SCHOOL   O,     MEDICINE,    EDINBURGH 


WITH  TABLE  AND  MAP 
\ 


EDINBURGH 

WILLIAM    F.   CLAY,    i8   TEVIOT   PLACE 

1895 


^.. 


EDINBURGH:   PRINTED  FOR  WILLIAM  F.  CLAY 
18   TEVrOT   PLACE 


LONDON:   SIMPKIN,  MARSHALL,  HAMILTON,  KENT,  &  CO.,    LIMITED 


[A/i  Rights  reserz'e.t] 


L'lb    . 


PREFACE. 


As  mentioned  in  the  introductory  paragraph,  these  pages, 
treating  of  the  climatology  of  Africa  and  the  distribution  of 
disease  in  that  continent,  were  written  at  the  request  of  the 
Committee  of  the  African  Ethnological  Congress,  which 
assembled  at  Chicago  in  1893. 

An  abstract  of  the  paper  was  read  before  the  Congress, 
and  it  was  published  in  full  in  the  Proceedings  of  the  Royal 
Physical  Society  of  Edinburgh,  vol.  xii.,  part  2. 

At  the  request  of  many  interested  in  the  subject,  I  venture 
to  publish  this  very  brief  contribution  to  the  literature  upon 
tropical  disease  in  Africa. 

The  text  stands  as  it  was  written  in  the  early  part  of  1893, 
but  the  map  and  chart  have  been  corrected  up  to  date. 

The  Appendix  —  a  paper  read  before  the  Congress  of 
Hygiene  and  Demography  at  Budapest,  in  1894 — treats  of 
a  new  method  of  illustrating  graphically  the  distribution  of 
disease  in,  and  the  climatology  of,  any  area. 

I  beg  to  acknowledge  my  indebtedness  to  numerous 
authors  from  whom  I  have  gained  information,  in  regard 
especially  to  those  parts  of  Africa  with  which  I  have  no 
personal  acquaintance. 

E.  w.  r. 


8  Alva  Street, 
Edinburgh,  January  1895. 


IW350J^7() 


INDEX. 


PACK 

PAGB 

Abyssinia, 

22,  23 

Egyptian  Delta, 

21 

Acclimatisation, 

4 

Elephantiasis  arahimi, 

62 

Alrica — 

Enteric  fever. 

67 

Altitude  of. 

6 

Ecjuatorial  Africa, 

.     37-42 

Characteristics  of  native? 

9,  10 

Eniigratiou  to,     . 

11 

Gold  Coast,     . 

26 

E:lniologicHl   distribution 

Guinea-worm, 

.     57-59 

of  population  of. 

9 

Fauna,     . 

8 

Hannoglohinuria, 

75 

Geology  of. 

5 

Lakes  of. 

6 

Lagos, 

26 

Mortality  in  tropical  dis 

Leprosy, 

63 

triers  of, 

14 

Population  of, 

9 

Madagascar,    . 

45 

Kainfall, 

8 

Malaria, 

.    70-75 

U-ligion, 

10 

Mashonaland, 

43 

'lenrperature, 

7 

MataV'eleland, 

43 

Vertical  zones  of  climate 

Mauritius, 

46 

in,         . 

12 

]\Iorofco, 

IS 

Zones  of  vegetation, 

S 

Mortality  in  AVest  Coast, 

14 

African  climate — 

Constitutions  most  suited 

Natal, 

44 

for,       .             . 

49,  50 

Native  treatment  of  disease 

.     47-49 

Effects  on  eraigrauts, 

15 

N'ger  district, 

27 

Effects  on  women, 

16 

African  date-mark. 

54 

Orange  Free  State, 

43 

Ainhum, 

51 

Oriental  sore,  . 

54 

Algeria, 

19 

Altitude,  effects  on  disease,    . 

12,  13 

Phthisis,          .             .          'i 

^3,  40,  44 

Benguela, 

27 

Red  Sea  Coast, 

21 

Beri-heri, 

51 

Remittent  fever,  see  Malaric 

Bilharzia  hcematuria, 

52,  53 

Black-water  fever , 

75 

Sahara, 

37 

Senegimbia,    . 

26 

Cape  Colony,  .             . 

44,  45 

Sfjcnt-Ues, 

46 

Characteristics  of  natives. 

9,  10 

Sierra  Leone,  . 

26 

Climate,  vertical  zones  ot, 

12 

Snake  bites,     . 

60 

Congo, 

27 

Soudan, 

37 

South  Africa, 

42 

Delta,  of  Nile, 

21 

Dengue, 

54-57 

Transvaal, 

24 

Disease,   iniluence  of  altitud 

2 

Tunis  and  Tripoli, 

20 

on, 

12,  13 

Typhoid  fever. 

67 

Disease,  native  treatment  of, 

47-49 

Diarrhoea, 

68-70 

West  Coast  of  Africa, 

.    27-36 

Dysentery, 

68-70 

Yaws, 

61 

East  Coast  of  Africa,  . 

23 

Yellow  fever,  . 

.     64-67 

Egypt,             .     _        . 

21,  22 

Egyptian  chlorosis, 

59 

Zai.zibar,  vide  East  Coast. 

ON  THE 

GEOGEAPHICAL  DISTEIBUTION   OF 
TROPICAL  DISEASES  IN  AFRICA. 


The  origin  of  this  small  work  was  a  request  from  the 
committee  of  the  African  Ethnological  Congress,  at  the 
World's  Eair  in  Chicago,  that  I  should  lecture  for  them  on 
"  Disease  and  Medicine  in  Africa."  In  preparing  that  lecture, 
I  was  desirous  of  illustrating  the  climatology  of  Africa  and 
the  distribution  of  disease  on  a  map,  and  the  one  which 
accompanies  this  little  work  was  the  result  of  my  endeavours. 
Few  maps  have  been  published  illustrating  the  geographical 
distribution  of  disease,  and,  in  the  one  I  have  constructed, 
I  have  attempted  a  somewhat  new  departure,  I 
have  divided  Africa  into  eight  regions,  each  having  ap- 
proximately the  same  climatology,  and  in  each  of  these 
zones  I  have  introduced  symbols  to  demonstrate  the 
diseases  present,  I  have  also  endeavoured,  by  repeating  the 
symbols,  to  show  the  prevalence  or  the  importance  of  the 
disease.  Where  one  symbol  occurs,  the  disease  it  represents 
is  present  in  the  area ;  if  two  symbols  are  marked  on  the 
map,  the  disease  is  very  prevalent;  and  where  three  symbols 
occur,  the  disease  is  exceedingly  rife,  or  the  mortality  from 
it  excessive.  A  mere  glance  at  the  map  will  show  the 
amount  of  disease  in  any  area,  and  the  comparative  salubrity 
or  unhealthiness  of  a  district  is  at  once  seen.  This,  I  trust, 
will  be  useful,  especially  as  the  rush  to  Africa  still  con- 
tinues, and  extensive  schemes  of  colonisation  are  in  the  air. 

When  the  map  I  have  prepared  is  compared  with  one 
showing  altitude,  the  reason  for  the  presence  or  absence  of 
many  diseases  is  at  once  understood. 

After  describing  the  climatology  of  the  various  regions 


4  Oil  the  Geographical  Distribution  of 

iuto  which  I  have  divided  Africa,  and  enumerating  the 
diseases  met  with  in  each  area,  I  have  added  a  short  descrip- 
tion of  the  tropical  diseases  met  with,  adding  some  remarks 
upon  their  probable  origin,  their  prevention,  and  treatment. 
This,  I  tlnnk,  may  be  of  some  use  to  travellers  and  others 
visiting  tlie  continent. 

Notwithstanding  the  progress  which  has  been  made  in 
medicine,  in  climatology,  and  in  economics,  even  now  we 
know  little  or  nothing  as  to  the  effects  of  climate  upon  the 
Imman  organism.  The  subjects  of  acclimatisation,  acclima- 
tion, and  the  survival  of  the  fittest,  are,  it  is  true,  touched 
upon  by  many  authors,  and  it  seems  to  be  the  idea  of  many 
that  these  problems  are  more  or  less  settled.  This,  however, 
is  not  the  case. 

As   a   rule,   authors   writing   on   Anglo-Saxon    e.Ktension 
proceed  on  the  d  prioy-i  assumption  that  the  Anglo-Saxon 
race  can  live  and  thrive  more  or  less  all  over  the  world;  and 
again,  they  assume  that  wheresoever  this   race  may  dwell 
they  will  remain,  morally  and  physically,  as  they  previously 
existed  in  their  original  habitat.     True,  some  wiser  writers 
do  recognise  the  patent  fact  that  Europeans  and  individuals 
from  the  Northern  States  of  America  cannot  compete  with 
the   coloured   races   in   the  Tropics.     Tiiey  allow  that   the 
supremacy  of  the  whites  in  the  Tropics  is  artificial,  wherever 
it    may   obtain.      There    the    white  races    only    keep    en 
evidence   practically   by  constantly   reinforcing  their   ranks 
through  importation.     Even  if  we  examine  into  the  con- 
dition which  obtains  in  Barbadoes,  where  the  British  have 
their    oldest    and,    possibly,   their    most    healthy    tropical 
possession,  we  find  that  a  cycle  of  constant  fresh  importation 
has  been  going  on  to  keep  up  the  stock.     It  is  true  that 
"  mean  whites "   may  indeed  be  found  there,  but  they  are 
the  degenerate  representatives  of  the  race.     In  the  Southern 
States  of  America,  good  authorities  tell  us  that  the  Negroes 
are,  owing  to  their  better  adaptation  to  the  climate,  gradually, 
but  surely,  replacing  the  whites.     Looking  for  a  moment  to 
New  Zealand,  which  is,  of  course,  not  a  tropical  country,  we 
find  that,  notwithstanding  the   fact  that   the   population  is 
constantly    receiving    fresh    British    blood,    it   diil'ers    in    a 


Tropical  Diseases  in  Africa.  5 

marked  degree  from  the  parent  stem,  owing  to  the  appar- 
ently inscrutable  action  of  climate  upon  human  beings.  It 
is  evident,  even  to  superficial  observers,  that  the  New 
Zealanders  are  mentally  different  from  the  original  stock, 
and  there  is,  doubtless,  also  some  amount  of  physical  alter- 
ation which,  were  sufficient  attention  paid  to  the  subject, 
would  be  found  to  be  important. 

It  would  be  interesting,  did  opportunity  allow,  to  indicate, 
with  some  attempt  at  detail,  the  causes  which  lead  to  these 
marked  changes,  which  are  noticeable  in  emigrants  and 
their  descendants,  but  one  remark  must  suffice;  the  hard 
winters  in  the  north  render  the  people  industrious,  provident, 
and  capable  of  great  endurance,  or  in  such  a  country  as 
New  Zealand  life  is  less  gloomy  and  anxious,  and  the  people 
are  more  lively — brighter — in  fact  more  mobile.  When,  how- 
ever, the  climate,  like  that  of  Africa,  is  enervating,  emigrants 
from  the  north  become  lazy,  indolent,  to  some  extent  emas- 
culated. National  character  is,  on  the  whole,  undoubtedly 
changed.  It  will  be  seen  in  the  sequel  what  conditions  to 
a  great  extent  produce  this  change  in  character,  and  in  the 
Tropics  a  change  in  physical  stamina,  likewise.  It  will  not 
be  possible,  however,  for  me  to  apply  the  facts  I  allude  to 
in  this  connection.  My  scope  is  a  more  limited  one,  but 
I  have  thought  it  well  to  call  attention  to  the  subject 
because  of  its  great  importance. 

Looked  at  in  the  light  of  modern  geology,  Africa  is  of 
great  antiquity.  The  origin  of  the  continent  belongs,  doubt- 
less, to  Archasan,  Paleozoic,  and  early  Mesozoic  eras.  In  round 
numbers  the  continent  has  an  area  of  9,858,000  geographical 
square  miles,  its  length  is  4330  geographical  miles,  and  its 
breadth  about  5000  miles.  It  is  situated  between  latitude 
37°  20'  40"  N.  and  latitude  34°  49'  15"  S.  The  coast-line  is 
remarkable;  it  is  only  some  17,700  miles  in  length.  This  is 
out  of  proportion  to  its  vast  area,  and  is  due  to  the  absence 
of  bays,  inlets,  or  estuaries.  The  configuration  of  the  continent 
of  Africa  is  peculiar.  It  may  be  described  as  possessing  a 
coastal  girdle,  having  a  varying  breadth  of  from  100  to 
300  miles  in  width.  This  girdle  bounds  an  enormous 
plateau,  which  slopes  from  the  east  towards  the  west,  and 


6  On  the  Geographical  Distribution  of 

in  the  main  axis  of  which,  running  from  S.W.  to  N.E., 
there  is  a  range  of  mountains,  broken,  it  is  true,  at  intervals. 

The  main  elevation  of  tlie  continent  is  less  than  that  of 
Europe  or  Asia;  an  oblique  line  drawn  from  Loanda  to 
Suakim  passes  through  a  table-land  varying  in  height  from 
oOOO  to  4000  feet.  It  is  remarkable  that  the  three  great 
rivers — the  Nile,  the  Congo,  and  the  Zambesi — have  their 
headwaters  almost  together,  so  low  is  the  watershed ;  and 
the  whole  river  system  of  Africa  renders  ready  drainage 
impossible,  and  thus  gives  to  it,  on  the  whole,  a  water-logged 
character,  especially  in  vast  areas  in  the  centre  of  the 
continent.  It  is  noteworthy  that  there  are  six  drainage 
areas  in  Africa,  three  inland  —  the  Sahara  Desert,  the 
Kalahari  Desert,  and  Eastern  Abyssinia  —  and  then  the 
Atlantic  Ocean,  the  Mediterranean  Sea,  and  the  Indian 
Ocean, —  the  drainage  area  towards  the  Atlantic  Ocean,  includ- 
ing as  it  does  the  river  systems  of  the  Niger  and  the  Congo, 
being  the  greatest.  With  the  exception  of  the  Nile,  whose 
discharge  is  only  about  one  thirty-seventh  of  the  rainfall  of 
the  river's  basin,  the  African  rivers  have  an  abnormal  volume 
of  discharge,  due  to  the  situation  of  their  mouths  in  the 
equatorial  zone,  and  the  excessive  rainfall  in  their  catch- 
ment basins. 

The  lakes  of  the  African  continent  may  be  divided  into 
three  classes — those  situated  in  the  continental  axis,  namely, 
the  Victoria,  Albert  and  Albert  Edward  Nyanzas,  Tanganyika, 
and  Lake  Nyassa,  possessing  fresh  water,  and  having  an 
oceanic  outlet;  secondly.  Lakes  Chad  and  Ngami,  which  lie 
in  continental  depressions,  and  vary  greatly  in  size  during 
the  various  seasons,  whose  water  is  more  or  less  saline ;  and 
lastly,  the  lakes  situated  along  the  course  of  the  great  rivers, 
and  which  are  simply  enormous  expansions  of  these,  caused 
by  the  heavy  rainfall  in  the  Tropics.  In  Central  Africa  the 
highest  mountains  are  Kenia  and  Kilimanjaro  in  the  east, 
and  Gambaragara  and  Ruwensori  in  the  centre,  having  an 
average  altitude  of  some  19,000  feet. 

Our  knowledge  of  the  climatology  of  Africa,  except  in 
northern  and  southern  districts,  is  very  inconqjlete,  and  this 
is  unfortunate,  because  an  exact  knowledge  of  the  climatology 


Tropical  Diseases  in  Africa.  7 

of  Central  Africa  would  be  of  the  utmost  interest  and  im- 
portance to  us  in  our  present  inquiry.  It  will,  however, 
probably  be  of  advantage,  before  dealing  with  the  climatology 
of  distinct  areas,  which  must,  of  necessity,  be  treated  separ- 
ately, to  give  a  summary  of  the  general  phenomena  of  the 
climate  of  the  whole  continent,  so  far  as  it  is  known. 

The  mean  annual  temperature  of  the  continent  of  Africa 
is  high.  There  is  a  strip  of  country  upon  the  east  coast 
from  lat.  23°  N.  to  lat.  23°  S.,  where  the  mean  annual 
temperature  is  over  80°  F.,  and  the  same  high  temperature 
obtains  in  two  other  regions.  One  of  these  is  towards  the 
west  of  the  Eed  Sea,  bounded  towards  the  north  by  Dongola, 
on  the  south  by  Lado  on  the  Nile,  on  the  west  by  about 
long.  25°,  and  on  the  east  by  Abyssinia  and  long.  36°.  The 
other  area  is  situated  towards  the  west,  bounded  on  the 
south  by  the  coast-line  between  Sierra  Leone  and  Lagos, 
on  the  west  by  long.  17°  W.,  on  the  east  by  long.  18°  to  20° 
K,  on  the  north  by  a  pyramidal  line  lowest  on  the  west  and 
east  at  lat.  16°  N.,  and  having  its  apex  at  lat.  28°  K,  long  0°. 
Apart  from  this,  with  the  exception  of  Morocco,  Algeria, 
Tripoli,  and  the  Nile  delta,  an  oblong  area  commencing  in 
Abyssinia,  and  running  down  to  the  equator,  Cape  Colony, 
Matabeleland,  Damaraland,  and  Angola,  where  the  mean 
annual  temperature  is  between  60°  and  70°  F.,  the  remaining 
part  of  the  continent  has  a  mean  annual  temperature  of  from 
75°  to  80°  F.  From  this  it  will  be  seen  that,  although 
along  the  northern,  western,  and  southern  coast-line  the 
temperature  is  to  some  extent  lowered  by  the  proximity  of 
the  ocean,  yet  on  the  east  the  sea  exerts  no  modifying  effect, 
but  practically  increases  the  temperature  5°  to  10°  F. 

With  regard  to  the  mean  annual  range  of  temperature  in 
Africa,  considerable  variations  exist.  There  is  a  district  which 
may  be  roughly  said  to  embrace  nearly  the  whole  of  the 
Congo  Free  State,  where  the  range  is  less  than  5°  annually, 
and  in  the  Sahara  we  arrive  at  the  other  extreme,  the  range 
being  there  between  40°  to  50°.  Practically,  from  lat.  18° 
N.  to  20°  S.,  the  annual  range  is  from  10°  to  20°.  With 
regard  to  relative  humidity,  it  is  over  70  per  cent,  over 
a  third  of  the  continent.     The  upper  boundary  of  this  area 


8  On  the  Geographical  Distribution  of 

may  be  described  as  a  line  drawn  from  Cape  Verd  to  Lado 
on  the  Whiite  Nile  on  the  north,  bounded  by  32°  E.  long,  in 
the  east  and  lat.  15°  S.  in  the  south,  and  including,  also,  the 
coast  belt  from  Cape  Town  to  lat.  2^  N.  on  the  east  coast. 
Apart  from  this,  with  the  exception  of  Abyssinia,  where  the 
humidity  is  also  over  70  per  cent,  it  is  considerably  less. 

The  rainfall  in  Africa  likewise  varies  greatly,  it  being 
under  5  inches  in  the  Sahara  and  in  the  Kalahari  Desert.  It 
is  over  100  inches  at  Sierra  Leone  and  between  Lagos  and 
Gaboon.  Over  the  remaining  part  of  the  continent  it  varies 
from  10  to  100  inches.  Speaking  generally,  the  annual  rain- 
lall  may  be  estimated  at  from  50  to  60  inches.  The  rainfall 
at  the  equator  is  pretty  evenly  distributed  throughout  the 
whole  year,  but  to  the  north  of  the  equator,  at  about  15°  lat., 
there  are  two  well-marked  rainy  seasons. 

With  reference  to  winds,  the  trade  winds  are  the  most 
important.  North  of  the  equator  the  prevalent  trade  winds 
are  from  the  north-east,  south  of  it  from  the  south-east,  with 
an  intervening  belt  of  calms  at  the  equator,  and  it  is  to  these 
Avinds  that  the  unequal  distribution  of  the  rainfall  is  to  be 
attributed. 

The  heat,  rainfall,  and  winds  naturally  affect  the  fertility 
of  the  country,  and  the  whole  area  of  Africa  may  be  divided 
up  as  follows  : — 364  per  cent,  is  occupied  by  deserts,  14  6  by 
steppes,  5-3  by  scrub,  21-3  by  savannahs,  21-8  by  forests  and 
cultivated  land,  and  6  per  cent,  by  the  large  lakes.  Therefore 
half  the  continent  is  occupied  by  deserts  and  steppes. 

The  typical  zones  of  vegetation  are — (1)  the  Mediterranean 
zone,  having  a  vegetation  similar  to  that  of  southern  Europe, 
if  somewhat  more  tropical ;  (2)  the  Sahara  Desert  zone,  of 
which  much  might  be  cultivated,  numerous  oases  certainly 
existing  there ;  (3)  the  zone  of  tropical  vegetation,  more  or 
less  coincident  with  the  areas  of  the  highest  mean  annual 
temperature  and  heaviest  rainfall;  and  lastly,  the  south- 
central  and  South  African  savannah  zone.  In  general  terms, 
the  vegetation  is  richer  as  we  proceed  from  the  south  to 
the  north,  and  also  Iroui  the  west  to  the  east. 

It  is  unnecessary  to  refer  in  detail  to  the  fauna  of  Africa. 
The  mammalian  fauna  is  exceptionally  varied,  the  bird  fauna 


Tropical  Diseases  in  Africa.  9 

meagre,  the  reptile  fauna  largely  developed.  Insect  life  is 
very  abundant,  and  the  tetze  fly  infests  large  parts  of  the 
country  which  are  uncleared. 

The  population  of  Africa  may  be  estimated  at  about  20  to 
a  square  mile.  Boehm  and  Wagner  estimate  the  population 
at  205  millions,  Mr  Eavenstein  at  127  millions,  with  a  rate 
of  increase  of  10  per  cent,  per  decade. 

The  people  of  Northern  Africa  were  probably  in  pre- 
historic times  of  the  same  ethnical  stock  as  that  of  the  people 
inhabiting  Southern  Europe.  The  Arabs  of  the  Soudan  are 
probably  all  descendants  from  the  proto-Semitic  stock.  For 
the  rest  we  have  Negroes  of  various  kinds,  but  all  distinguished 
by  projecting  jaws,  flat  features,  broad  noses,  woolly  hair, 
shining  skin,  and  pouting  lips,  and  it  is  probable  that  they 
are  all  of  one  origin.  We  find  also  in  Africa  the  Bushman 
and  Tikki-Tikki  or  Akka  dwarfs,  all  of  whom  I  believe  to  be 
among  the  oldest  primitive  inhabitants  of  the  continent. 

In  classifying  the  ethnographic  distribution  of  a  population, 
it  is  best  to  be  guided  by  linguistic  facts;  but,  as  according  to 
Cust  there  are  no  less  than  438  languages  and  153  dialects 
spoken  in  Africa,  such  a  classification  is  for  present  purposes 
impossible,  and  therefore  I  adopt  Miller's  classification  of 
distinct  groups,  as  follows  :— (1)  The  Semitic  family,  along 
the  north  coast  of  Africa  and  of  Abyssinia ;  (2)  the  Hamitic 
family,  who  dwell  mainly  in  the  Sahara,  Morocco,  Algeria, 
Egypt,  and  in  the  Galla  and  Somali  districts ;  (3)  the  Eulah 
and  Nuba  groups,  who  live  in  the  western  central  and  eastern 
Soudan ;  (4)  the  Negro  groups,  in  the  western  and  central 
Soudan,  in  Upper  Guinea  and  the  Upper  Nile  region ;  (5)  the 
Bantu  family,  everywhere  south  of  4°  N.  lat.,  except  in  the 
Hottentot  domain  ;  (6)  the  Hottentot  group,  in  the  extreme 
south-western  corner  of  Africa,  from  the  Tropic  of  Capricorn 
to  the  Cape ;  (7)  the  Tikki-Tikkis  and  Akkas,  living  in 
scattered  groups  to  the  north  of  the  equator. 

A  few  sentences  with  regard  to  the  general  characteristics 
of  these  people  are  necessary,  to  show  their  possible  predis- 
position to  certain  diseases,  their  immunity  from  others. 
The  inhabitants  of  Africa  have,  on  the  whole,  a  well-developed 
muscular  system.      Mentally  they  are  like  children,  easily 


10  On  the  Geographical  Distribution  of 

amused  and  easily  roused  to  passion.  They  possess  innate 
capabilities  of  high  education,  but  it  is  a  mistake  to  suppose 
that  the  average  Negro  child  can  be  educated  up  to  the 
European  standard.  Till  the  age  of  fourteen  he  will  probably 
distance  a  European  child  in  almost  all  brain  work,  but  after 
this  age  the  light-skinned  Caucasian  shoots  ahead  of  the 
dusky  child  of  the  Tropics.  As  a  rule,  at  least  three  genera- 
tions are  necessary  to  develop  the  Negro  to  our  mental 
standard.  Owing  to  the  climatological  factors  to  which  I 
have  referred,  the  natives  possess  a  lethargic  constitution. 
Nature  being  so  bountiful,  they  have  no  incentive  to 
strenuous  manual  labour.  But  there  is  a  marked  difference 
between  the  inhabitants  of  the  mountainous  regions  of  the 
Tropics  and  those  inhabiting  the  low-lying  plains.  For 
instance,  the  inhabitants  of  the  northern  and  higher  parts  of 
Uzinza  are  far  more  strongly  built  and  energetic  than  the 
Wazinza  who  inhabit  the  southern  and  lower  parts  of  the 
country.  Such,  at  any  rate,  was  the  opinion  of  Speke,  and  I 
have  personally  noticed  the  same  characteristics  north  of  the 
equator. 

Again,  the  religion  and  customs  of  the  inhabitants  neces- 
sarily influence  their  susceptibility  to  disease,  or  their  power 
of  recovery  after  having  been  attacked  by  disease.  There  is 
a  marked  difference  between  the  stolid,  fatalistic,  Moham- 
medan and  the  superstitious  pagan.  A  difference  also 
obtains  in  many  districts  owing  to  diet,  partly  influenced  it 
is  true  by  custom,  but  also  by  religion,  and  the  vegetarians 
and  mixed  feeders  are  liable  to  definite  varieties  of  disease. 

Although  it  is  a  mistaken  notion  that  insanity  and  nervous 
diseases  do  not  obtain  among  the  natives,  yet  they  are 
undoubtedly  less  frequent  in  Africa  than  they  are  in 
temperate  latitudes ;  and  it  is  certain  that  civilisation,  or,  at 
any  rate,  contact  with  the  whites,  has  a  more  or  less  deterio- 
rating effect  upon  the  native  population. 

It  is  now  necessary  to  refer  briefly  to  the  subject  of 
acclimatisation,  and  to  endeavour  to  answer  the  question 
which  is  frequently  put— Can  Europeans  become  acclimatised 
in  Tropical  Africa  ? 

My  strong  opinion  is  that  it  can  only  be  possible  if  migra- 


Tropical  Diseases  in  Africa.  11 

tion  occurs  step  by  step,  and  in  estimating  the  possibilities 
of  acclimatisation  we  must  count  by  generations  rather  than 
by  years.  I  believe,  however,  that  our  increased  knowledge 
of  climatology  and  hygiene  renders  the  problem  of  acclimatisa- 
tion more  easy  of  solution  than  it  was,  and,  given  picked 
individuals  and  the  careful  selection  of  tropical  areas  in 
which  to  colonise,  I  see  no  reason  why,  with  precautions, 
inhabitants  of  the  temperate  zone  should  not  colonise  even 
in  Central  Africa.  In  the  selection  of  emigrants,  great 
care  should  undoubtedly  be  taken,  and  all  persons  with  a 
tendency  to  gout  or  rheumatism,  diabetes  or  albuminuria, 
those  with  a  nervous  or  alcoholic  family  history,  or  those 
sufteving  from  either  acquired  or  hereditary  syphilis,  should 
certainly  be  restrained  from  emigrating  to  Tropical  Africa. 

As  I  before  indicated,  environment  definitely  influeuces  not 
only  individuals  but  nations,  and  for  this  reason  a  marked 
difference  obtains  between  the  adaptability  of  residents 
in  the  northern  and  southern  parts  of  a  temperate  zone 
for  acclimatisation  purposes.  Individuals  and  nations  are 
not  only  influenced  by  the  climatology  of  their  original 
residence,  but  also  by  their  habits  and  customs  and  their 
psychical  peculiarities.  It  has  been  found,  as  was  pointed 
out  long  ago  by  Mr  Eavenstein,  that  the  peoples  of  Southern 
Europe,  such  as  the  Italians  and  southern  Frenchmen,  can 
withstand  the  climate  of  sub-tropical  Africa  better  than  can 
northern  Europeans.  "  A  steady  stream  of  migration  is  in 
fact  setting  in,  in  that  direction.  Germans  and  Belgians  are 
pouring  into  France  ;  Frenchmen  are  going  to  Algeria ;  the 
Arabs  from  the  shores  of  the  Mediterranean  have  found  their 
way  into  the  Soudan  ;  whilst  the  Soudanese  are  pushing 
forward  into  Bantu  Africa.  A  similar  movement  is  going  on 
in  South  Africa.  The  descendants  of  those  Dutchmen  who,  a 
couple  of  hundred  years  ago,  first  settled  at  the  Cape  have 
made  their  way  to  the  Transvaal ;  and  European  migration, 
favoured  by  geographical  features,  is  being  pushed  even 
within  the  Tropics  towards  the  Zambesi." 

This  agrees  with  my  own  opinion,  that  wholesale  immediate 
acclimatisation  for  Europeans  in  Tropical  Africa  is  entirely 
out  of  the  question. 


12  On  the  Geographical  Distribution  of 

But  it  may  be  said,  What  about  the  high  African  table- 
land ?  Wliat  about  the  mountainous  rej^ions  ?  As  it  is 
customary  to  speak  of  three  climatological  zones — the  hot, 
the  temperate,  and  the  cold — between  the  equator  and  the 
poles,  so  in  like  manner  we  can  say  that  in  the  Tropics  there 
are  three  vertical  zones  of  climate.  (1)  A  zone  extending  up 
to  a  height  of  3000  feet,  having  a  mean  annual  temperature 
of  from  72°  R  to  83°  F.— the  hot  zone ;  (2)  a  zone  from 
3000  to  12,000  feet,  with  a  mean  annual  temperature  of  from 
41°  to  72°  F. — the  temperate  zone;  (3)  a  zone  from  12,000 
to  16,000  feet  or  above,  with  a  mean  annual  temperature  of 
from  30°  to  41°  F. — the  cold  zone.  Each  zone  has  peculi- 
arities of  its  own  with  regard  to  the  presence  or  absence  of 
disease,  and  the  higher  the  altitude  of  the  region  within 
certain  limits,  the  more  nearly  it  approaches  the  climate  of 
Europe.  As  we  proceed,  however,  north  or  south  of  the 
equator,  the  boundaries  of  those  zones  are  found  at  gradually 
decreasing  elevations,  and  therefore  heat,  atmospheric  pres- 
sure, etc.,  vary  at  different  latitudes. 

The  influence  of  these  zones  upon  disease  is,  broadly 
speaking,  as  follows: — In  the  upper  or  cold  zone  there  is  a 
tendency  to  plethora;  the  disorders  met  with  are  of  an 
intlammatory  character,  and  the  diseases  of  the  respiratory 
and  circulatory  organs  are  far  from  uncommon.  Malaria, 
yellow  fever,  cholera,  phthisis,  dysentery,  and  hepatitis  are 
almost  entirely  absent.  The  absence  of  phthisis  is  probably 
due  to  the  rarification  of  the  atmosphere,  the  absence  of 
yellow  fever  to  the  lower  temperature,  as  well  as  on  account 
of  the  distance  from  the  sea. 

Areas  situated  at  these  high  altitudes  are  incomparably 
superior  to  the  low-lying  districts.  As  a  rule  they  are 
entirely  free  from  tropical  endemic  diseases,  which,  should 
they  perchance  be  introduced,  rarely  spread.  A  marked 
difference  is  soon  noticed  in  the  appearance  of  individuals 
who,  after  a  residence  in  low-lying  tropical  countries,  go  to 
the  hills  or  elevated  tablelands.  Their  vigour  improves 
rapidly,  they  almost  regain  the  healthy  appearance  they  had 
in  Europe,  their  digestion  and  the  composition  of  their  blood 
is  improved,  and  a  proper  amount  of  exercise  can  be  taken. 


Tropical  Diseases  in  Africa.  13 

"Hill  diarrhoea"  and  rheumatism  may  sometimes  affect 
them  in  these  higher  altitudes.  The  former  may  be  due  to 
either  a  faulty  water-supply  or  a  too  rapid  removal  from  the 
plains  ;  the  latter — as  in  India — to  damp  dwellings,  or  to 
the  more  marked  vicissitudes  of  climate. 

Tlie  middle  zone  is  perhaps  best  divided  into  two,  which 
we  may  compare  with  the  temperate  and  sub-temperate 
zones,  the  cooler  (higher)  having  a  mean  annual  temperature 
of  from  41°  F.  to  55°  F.,  the  warmer  (lower)  a  mean  annual 
temperature  of  from  55°  to  73°  F.  In  both  these  areas  the 
seasons  exert  an  inllaeuce,  and  therefore  the  presence  and 
prevalence  of  disease  fluctuate,  the  frequency  of  diseases  of 
the  respiratory  and  digestive  organs,  for  example,  rising  and 
falling  correspondingly;  but  throughout  this  region,  as  a 
whole,  diseases  specially  frequent  in  the  higher  and  lower 
zones  are  less  virulent  in  character. 

The  lowest  or  hot  zone  is  the  typical  tropical  disease  zone. 
Here  we  meet  with  anosmia,  malaria,  diseases  of  the  gastro- 
intestinal tract,  hepatitis,  dysentery,  diarrhoea,  beri-beri, 
dengue,  yellow  fever,  etc.  Various  diseases,  however,  are 
not  met  with,  such  as  typhus,  plague,  goitre  and  cretinism, 
and,  for  the  most  part,  diseases  of  the  kidneys.  It  is 
obvious  that  inhabitants  of  the  temperate  zone  dwelling  in 
this  lowest  or  hot  zone  must  be  injuriously  affected  by  the 
climate,  and  probably  the  greatest  injurious  eflect  they  sus- 
tain is  due  to  the  heat  and  equable  temperature,  the  tonic 
effects  of  the  cold  season  being  sorely  missed,  in  consequence 
of  which  there  is  a  gradual  sinking  of  the  vital  energy. 
Moisture  is  the  next  injurious  element,  for  dry  heat  is  much 
less  injurious  to  such  emigrants  than  a  hot  moist  atmosphere. 
The  character  of  the  soil  exerts  a  not  inconsiderable  in- 
fluence, low-lying  clayey  soil,  soil  rich  in  mould,  and 
alluvial  soil,  acting  injuriously;  dry  or  sandy  soil  being 
less  injurious.  If  the  soil  be  marshy,  temperature  is  lowered, 
and  it  is  found  that  by  draining  the  soil  the  temperature  will 
be  raised  2  or  3  degrees.  The  drier  the  soil  the  greater  the 
heat  during  the  day,  and  the  greater  the  cold  by  night,  owing 
to  the  rapidity  with  which  the  soil  cools  by  radiation.  Vegeta- 
tion also  influences  the  salubrity  of  these  regions,  for  where 


14  0)1  the  Geof/raphical  Distribution  of 

it  is  abundant,  the  temperature  will  be  more  equal,  the 
vegetation  preventing  the  sun  from  heating  the  ground,  and 
also  preventing  radiation  during  the  night.  Lakes  also 
exert  an  influence,  by  preventing  much  variation  between 
the  temperature  of  day  and  night. 

A  good  deal  is  written  concerning  the  high  rate  of 
mortality  in  tropical  regions,  but  in  comparing  the  salubrity 
of  areas  in  the  temperate  zone  and  in  the  tropics,  it 
is  often  left  out  of  mind  that  much  of  the  salubrity  of 
Europe  is  due  to  artificial  causes — to  the  prevention  of 
disease,  to  sanitary  measures,  to  the  care  of  the  sick  and 
infirm,  and  to  the  superior  medical  knowledge  of  our  law 
and  civilisation.  This  fact  can  be  at  once  appreciated  when 
we  consider  the  state  of  health  and  rate  of  mortality  in 
different  European  states ;  and  when  we  find  such  marked 
contrasts  as  are  presented  in  Great  Britain  and  liussia  for 
instance,  we  observe  that  locality  alone  does  not  cause  the 
sreat  difference,  and  that  it  is  not  climate  alone  which 
influences  disease  and  mortality. 

The  general  salubrity  of  any  place  may  be  ascertained 
from  the  death-rate ;  in  fact  it  is  the  only  criterion  we  have. 
A  low  death-rate — say  20  per  thousand — indicates  that  the 
climate  and  sanitary  surroundings  must  be  good.  If  the 
death-rate  be,  say  60  per  thousand,  either  climate  or 
sanitation  must  be  at  fault.  In  speaking  of  a  "  bad " 
climate  in  Africa,  it  must  not  be  forgotten  that  what  is 
meant  is  that  the  climate  is  bad  for  emigrants  from  the 
temperate  zone,  not  necessarily  that  it  is  bad  for  the  natives. 
Take,  for  instance,  the  west  coast  of  Africa.  The  climate  is 
not  on  the  whole  fatal  to  natives,  and  their  death-rate  is  not 
immoderately  high,  although  the  district  goes  by  the  name 
of  "  the  white  man's  grave."  There  are,  it  is  true,  exceptional 
areas  where  even  the  mortality  amongst  natives  is  great,  but 
so  too  in  the  temperate  zone  there  are  areas  where,  owing 
to  faulty  sanitation,  overcrowding,  and  the  like,  a  state  of 
matters  inimical  to  health,  and  inducing  a  high  rate  of 
mortality,  is  to  be  found.  A  few  statistics,  taken  hap- 
hazard, will  show  what  I  mean.  The  death-rate  in 
Edinburgh  in  1887  was  198  per  thousand;  in  Manchester 


Tropical  Diseases  in  Africa.  15 

in  the  same  year,  287;  in  New  York,  1878-80,  26-2;  in 
Chicago,  during  the  same  period,  27"2 ;  in  St  Louis,  19-3; 
in  Calcutta,  31*1. 

Very  much  may  be  done  to  render  even  the  worst  climate 
in  Tropical  Africa  more  salubrious,  and  the  sanitary  pre- 
cautions, to  which  attention  will  be  called  in  the  sequel, 
will  do  a  great  deal  to  raise  the  health  of  the  community. 
For  instance,  attention  to  the  water-supply  at  Sierra 
Leone  has  had  a  very  marked  effect  in  lowering  the 
death-rate;  but  when  all  is  done,  a  permanent  residence 
for  inhabitants  from  the  temperate  zone  is  at  present  out 
of  the  question  in  the  low-lying  regions  of  Tropical  Africa. 

We  must  now  briefly  consider  the  effects  which  the 
African  climate  exerts  upon  emigrants  from  the  temperate 
zone,  and  which  are  chiefly  the  results  of  heat  and  moisture. 
For  a  short  time  after  the  arrival  of  such  an  emigrant  in 
Tropical  Africa  his  health  remains  good,  in  fact  the  heat  seems 
to  have  a  stimulating  effect  upon  him.  He  does  not  suffer 
from  the  heat  of  the  sun,  and  he  forms  a  striking  contrast  to 
those  emigrants  who  have  resided  in  the  same  district  for  a 
considerable  time.  His  work,  be  it  mental  or  bodily,  is 
performed  with  comparative  ease.  Soon,  however,  he  begins 
to  experience  a  marked  change  in  the  physical  functions  of 
his  body.  Its  normal  temperature  is  about  1°  F.  higher 
than  it  was  in  the  temperate  zone,  his  respirations  are 
considerably  below  the  normal  number,  his  heart's  action  is 
increased  in  frequency,  his  digestive  powers  become  weak- 
ened, his  skin  secretes  far  more  freely  and  becomes  somewhat 
swollen,  his  urine  is  lessened  in  quantity,  and  his  nervous 
system  is,  to  a  greater  or  less  extent,  enfeebled.  There  is  no 
doubt  that  very  soon  his  mental  and  bodily  powers  become 
weakened,  this  being  due  to  modified  nutrition.  He  suffers 
from  anasmia  and  from  a  slightly  congested  liver.  The 
ansemia,  if  only  slight,  may  be  considered  as  prophylactic  in 
character,  and  the  congestion  of  the  liver  is  only  what  might 
be  expected  on  account  of  the  increased  work  that  that  organ  is 
compelled  to  perform.  The  resistance  which  an  individual 
from  the  temperate  zone  can  offer  to  these  conditions  depends 
on  the  height  of  the  mean  annual  temperature,  and  also  to 


1 6  On  the  Geographical  Distribution  of 

some  extent  on  its  diurnal  variation.  If  the  temperature  is 
high  during  tlie  whole  year,  he  is  less  able  to  withstand  them 
than  he  would  be  were  there  marked  dill'erences  in  the 
temperature  of  the  various  seasons,  or  between  that  of  night 
and  day.  This  power  of  resistance  may  also  be  attained  by  a 
change  of  air,  at  stated  intervals,  to  a  place,  either  having  a 
high  altitude,  or  where  marked  diurnal  variation  in  tem- 
perature occurs.  The  difficulty  experienced  in  Africa  at  the 
present  time  is,  that  comparatively  few  high  altitude  stations 
are  known,  and  some  considerable  number  of  years  must  elapse 
before  arrangements  can  be  made  to  provide  access  to  those 
areas  where  the  emigrant,  enervated  by  the  heat  and  mois- 
ture, may  seek  the  restoration  provided  by  a  residence  at  a 
high-level  station. 

A  word  in  passing  as  to  the  influence  of  the  African 
climate  upon  women.  Practically,  although  women  do  not 
suffer  so  much  as  men  from  malarial  fever,  this  is  prob- 
ably due  to  their  not  being  so  much  exposed  to  its  influence. 
Taking,  however,  all  things  into  consideration,  I  have  come 
to  the  conclusion  that  neither  sex  is  more  capable  than  the 
other,  of  withstanding  the  climate.  With  regard  to  children, 
it  may  be  said  that  the  same  condition  obtains  in  Africa  as 
in  India.  Apart  from  accidental  diseases,  children  will  do 
well  for  the  first  three  or  four  years  of  life,  but  under  exist- 
ing circumstances  they  must  then  be  sent  to  a  temperate 
climate  if  they  are  to  survive.  Were  they  to  remain  in 
Tropical  Africa,  they  would  certainly  degenerate  mentally, 
morally,  and  physically. 

I  have  now  come  to  the  end  of  my  extremely  rapid  survey 
of  the  general  facts  which  obtain  in  Africa  with  relation  to 
the  subject  of  my  paper,  and  I  now  proceed  to  describe, 
solely  from  the  point  of  view  of  health  and  disease,  the 
various  regions  into  which  Africa  may  be  divided,  and  to 
indicate  the  special  tropical  diseases  which  obtain  in 
them.  Wlien,  then,  the  area  of  the  distribution  of  the 
diseases  of  Africa  has  been  geographically  defined,  I  shall  pro- 
ceed to  briefly  examine  each  tropical  disease,  the  conditions 
under  which  it  arises,  and  its  prevention  and  treatment, 
seriatim. 


Tropical  Diseases  in  Africa.  17 

For   my  present  purpose  I  can  divide  the  continent  of 
Africa  into  eight  distinct  divisions,  namely, — 

I.  Northern  Africa,  including  Morocco,  Algeria,  Tunis, 
and  Tripoli. 
II.  North- Eastern  Africa,  including  Egypt  and  Abyssinia. 

III,  Eastern  Africa,  including  the  Islands  of  Zanzibar  and 

Pemba. 

IV.  West  Coast  of  Africa. 

V.  North  Central  Africa,  comprising  the  Sahara  and  the 

Soudan. 
VI.  South   Central    Africa,   extending   to   about    18°    S. 
latitude, 
VII.  South  Africa. 
VIII.  The    Islands   of    Madagascar,    Mauritius,   and    The 
Seychelles, 


1 8  On  the  Geographical  Distribution  of 

I.  Northern  Africa. 

This  part  of  Africa  has  its  climate  modified  by  its  proximity 
to  the  Mediterranean  and  Atlantic,  and  also  by  the  ranges 
of  mountains  running  parallel  to,  though  at  some  distance 
from,  the  coast.  It  naturally  falls  into  various  political 
divisions. 

1.  Morocco  is  a  dry  and  healthy  country.  It  has  a  moist 
and  fairly  equable  climate.  There  are  two  seasons — 
September  to  May  being  the  winter,  in  which  the  rainfall 
is  about  30  inches,  and  the  temperature  varies  from  50°  F. 
to  G5°  F.  The  summer,  almost  rainless,  has  a  temperature 
of  65°  to  80°  F.  Throughout  the  whole  year  the  daily  varia- 
tion of  temperature  is  remarkably  slight. 

The  diseases  specially  met  with  in  ^lorocco  are  dysentery 
and  diarrhoea,  which  are  very  prevalent  along  the  coast; 
and  leprosy,  syphilis,  and  ophthalmia,  which  are  very  common 
throughout  the  whole  country.  Chronic  rheumatism  is 
prevalent,  scrofula  not  uncommon,  but  respiratory  diseases 
and  the  eruptive  fevers,  with  the  exception  of  small-pox,  are 
rarely  seen.  Malaria,  manifested  by  intermittent  fever,  only 
obtains  in  a  slight  degree.  Epidemics  of  cholera  have  fre- 
quently visited  this  country,  as  also  all  the  countries  included 
in  Northern  Africa. 

2.  Algeria. — This  country  must  be  divided  into  two  parts 
— the  sea-coast  district,  called  the  Tell,  and  the  elevated  region 
beyond,  extending  to  the  summits  of  the  mountains,  which 
have  an  altitude  of  from  3000  to  8000  feet.  The  mean 
annual  temperature  is  about  65^  F.,  the  mean  diurnal  varia- 
tion 42°  F.,  the  nocturnal  variation  36°  F.  The  average  rela- 
tive humidity  is  about  45  per  cent.  The  rainfall  varies  in 
different  districts,  but  the  average  at  the  coast  is  about  900 
mm.  The  rain  commences  late  in  October,  and  ends  about 
the  end  of  March,  autumn  and  winter  occurring  within  this 
period.  Spring  begins  in  the  middle  of  March  and  ends  in 
June ;  July.  August,  and  September  being  the  summer 
months.  There  is  a  greater  amount  of  disease  in  Algeria 
than  in  eitiier  Morocco,  Tunis,  or  Tripoli.  The  death- 
rate  from  typlioid  fever  is  slightly  over  11   per  1000,  this 


Tropical  Diseases  in  Africa.  19 

disease  being  extremely  common,  especially  in  the  towns. 
Diphtheria  and  croup  are  also  widely  prevalent,  being  15  per 
1000  ;  diarrhoea  and  gastro-intestinal  disorders  rather  over  29 
per  1000.  Dysentery  also  is  very  prevalent,  especially  in  the 
district  of  Oran,  where  it  is  said  to  be  due  to  the  special 
character  of  the  water.  Small-pox  and  measles  are  to 
be  found  in  Algeria,  and  both  acute  and  chronic  bronchitis 
and  pneumonia  are  very  frequently  met  with.  This  is  con- 
trary to  what  one  might  have  expected.  With  regard  to 
phthisis,  the  death-rate  is  high,  but  this  is  only  in  the  towns, 
and  is  caused  by  the  number  of  phthisical  patients  sent  to 
Algeria  in  the  hope  of  cure.  It  is  a  great  mistake  to 
send  patients,  in  whom  phthisis  has  become  well-developed, 
to  Algeria,  for,  although  the  climate  is  exceedingly  good 
for  those  in  whom  the  disease  is  either  threatening  or  is 
in  a  very  early  stage,  it  is  undoubtedly  prejudicial  to  those 
in  whom  it  has  taken  firm  hold.  Leprosy  and  Oriental  Boil 
are  extremely  common,  and  so  is  hepatitis,  both  the  acute 
and  chronic  varieties,  and,  especially  in  Oran,  tropical 
abscess  of  the  liver.  Syphilis  and  acute  rheumatism  do 
not  occur  nearly  so  frequently  as  in  Morocco.  Goitre  is 
prevalent  in  the  mountainous  regions.  Malaria  is  very 
prevalent  in  Algeria,  although  it  is  not  so  frequently  met 
with  as  formerly,  for  sanitary  science  is  beginning  to  make 
itself  felt,  and  so  diminishes  its  frequency.  It  is  not 
so  often  seen  in  the  province  of  Algiers  itself,  as  it 
is  in  those  of  Oran  and  Constantin,  in  which  districts  it  is 
about  twice  as  prevalent.  The  amount  of  fever  is  unequally 
distributed  throughout  the  year;  the  maximum  amount 
occurs  in  the  autumn,  the  minimum  between  December 
and  May.  July  and  October  appear  to  be  the  two  months 
when  fever  is  most  prevalent.  Undoubtedly  the  heavy  rain- 
fall from  November  to  February  diminishes  the  fever.  On 
the  whole  the  fevers  are  most  prevalent  in  marshy  areas  with 
a  sub-soil  of  clay,  but,  as  Colin  points  out,  there  are  localities 
infested  by  malarious  fevers  which  are  far  from  being  marshy. 
But  this  forms  one  of  the  peculiarities  with  regard  to  malaria, 
and,  as  I  shall  point  out  elsewhere,  is,  I  believe,  due  to  the 
height  of  the  ground-water.      Probably  the  most  malarious 


20  On  the  Geographical  Distribution  of 

districts  are  Mitidja,  Bona,  the  Plain  of  Egliris,  Gigelle,  the 
plains  of  Zig,  Habra,  Zeybouse,  and  of  Shotts,  also  the 
district  through  which  the  ]\Iacta  Canal  passes,  and  the 
borders  of  the  Fezara  Lake. 

3.  Tunis  and  Tripoli. — These  regions  are  for  the  most 
part  deserts,  having  a  mean  annual  temperature  of  about 
70°  R,  and  a  mean  annual  variation  of  about  30°  F.  Diph- 
theria, dysentery,  and  diarrhoea  are  very  prevalent,  the  two 
latter  diseases  being  especially  met  with  between  July  and 
October.  Syphilis  and  acute  and  chronic  rheumatism  are 
also  very  common,  but  diseases  of  the  lungs  and  liver 
exceedingly  rare.  Almost  the  whole  of  the  district  is 
malarious,  with  the  exception  perhaps  of  the  area  in  which 
is  situated  the  Lake  of  Bizerta,  and  also  Porto  Farina. 

Summarising  the  information  we  possess  with  regard  to 
Northern  Africa,  we  find  that  malaria,  dysentery,  diarrhcL'a, 
leprosy,  syphilis,  and  rheumatism  are  exceedingly  frequent ; 
but  it  seems  only  probable  that,  were  extensive  sanitary 
measures  adopted  in  the  various  countries  referred  to,  and 
especially  drainage  and  a  good  water-supply  provided,  the 
district  would  be  far  from  inimical  to  emigrants  from  the 
south  of  Europe,  and  the  climate  is  decidedly  favourable  to 
persons  suffering  from  incipient  phthisis.  Such  individuals 
should,  however,  spend  at  least  two  winters  and  the  inter- 
vening summer  in  North  Africa,  if  they  would  gain  any 
decided  benefit  from  a  sojourn  there.  It  is  not  altogether 
easy  to  estimate  the  progress  made  by  France  in  the 
colonisation  of  Northern  Africa,  but  on  the  whole  I  believe 
that  gradual  acclimatisation  is  taking  place,  and  that  in 
time  the  country  may  be  completely  and  successfully 
colonised  by  that  nation;  and  doubtless  Italians  and  Spanish 
would  fare  equally  well. 

II.  North-Eastern  Africa. 

In  this  division  of  my  subject  there  are  various  climato- 
logical  areas  to  be  considered — (1)  The  Delta;  (2)  the  Valley 
of  the  Nile ;  (3)  the  Eastern  Desert,  including  the  coast  of 
the  Ked  Sea;   and  finally  Abyssinia.     Part  of  the  country 


Tropical  Diseases  in  Africa.  21 

politically  known  as  Egypt  will  be  considered  under  the 
head  of  the  Soudan. 

1.  The  Delta. — This  area  is  humid,  but  the  annual  rainfall 
is  only  about  7  inches.  Northerly  winds  prevail.  The 
mean  annual  temperature  is  about  69°  F.,  and  the  diurnal 
variation  slight. 

2.  The  Valley  of  the  Nile. — The  climate  in  this  district  is 
very  different.  The  country  may  be  practically  said  to  be 
rainless.  At  Cairo  there  are  only  four  or  five  showers  a 
year,  and  in  Upper  Egypt  but  one  or  two.  The  mean  annual 
temperature  at  Cairo  is  about  72°  F.,  but  the  variation 
between  night  and  day  is  very  great.  At  Cairo  the  tem- 
perature may  be  as  high  as  110°  F.,  but  in  the  winter  it  may 
fall  to  below  32°  F.  The  marked  feature  in  the  Nile  Valley 
is  the  inundation  of  the  country  by  the  Nile,  which  begins  to 
rise  about  the  middle  of  June,  reaches  its  height  at  the 
beginning  of  October,  when  it  commences  to  fall,  and  it  must 
be  remembered  that  in  Upper  Egypt  the  river  forms  the  sole 
source  of  the  water-supply  to  the  country.  There  is  probably 
no  other  country  in  the  world  where  the  population  is  so 
dependent  upon  a  single  river,  and  unfortunately  the  Nile  is 
habitually  polluted  with  all  kinds  of  filth,  which  has  a 
great  effect  on  the  health  of  Egypt,  for  during  the  summer 
months,  when  the  Nile  is  low,  the  people  practically  imbibe  a 
solution  of  filth.  This  faulty  water-supply  undoubtedly 
causes  the  tremendous  mortality  amongst  the  child  popula- 
tion. Out  of  1000  children  born  in  Egypt,  496  die  before  the 
age  of  five  years  (H.  K.  Green).  It  would  be  quite  possible, 
although  the  cost  would  be  great,  to  improve  the  water- 
supply  ;  there  are  no  insuperable  engineering  difficulties  to 
be  encountered. 

3.  The  Eastern  Desert  and  the  Bed  Sea  coast  are  drier  and 
hotter  than  the  Nile  Valley  itself.  This  notwithstanding, 
the  country  is  salubrious.  The  heat  from  January  to  April 
is  almost  insupportable,  especially  during  the  southern 
khamseen,  which  is  a  dry  scorching  wind. 

With  regard  to  the  diseases  prevalent  in  these  regions, 
typhoid  fever,  relapsing  fever,  and  dysentery  are  very  pre- 
valent throughout  the  whole  country,  and  simple  febriculas 


22  On  the  Geographical  Distribution  of 

are  frequently  met  with.  Epidemics  of  cholera  have  often 
visited  Egypt,  but  plague,  which  used  to  be  endemic  here, 
has  not  reap])eared  since  1844.  Ophthalmia  is  extensively 
prevalent  all  over  Egypt.  It  is  said  that  about  a  fourth 
of  the  whole  population  of  Egypt  is  affected  by  the 
Anchylostotmim  duodcnale,  which  causes  the  Egyptian 
chlorosis.  Eound  worms  are  also  very  common,  and 
guinea-worms,  introduced  from  the  south,  are  not  infre- 
quently seen.  There  is  also  a  specific  affection  of  the 
urinary  passages  caused  by  the  Bilharzia  hcematohia,  the 
embryos  of  which  infest  the  drinking  water.  Small-pox  is 
epidemic ;  measles  and  scarlet  fever  are  frequently  seen,  and 
so  are  hepatitis  and  tropical  abscess  of  the  liver.  Phthisis 
is  very  rare,  except  among  the  Negro  population,  in  which  it 
is  frequently  met  with.  Eheumatism,  on  the  other  hand,  is 
frequent,  especially  at  Cairo.  Scrofula  affects  the  natives, 
leprosy  is  endemic,  and  syphilis  very  common.  On  the 
whole,  the  country  I  am  describing  is  remarkably  free  from 
malaria,  although  the  disease  is  present  in  the  autumn.  The 
greatest  number  of  cases  occurs  at  Suez,  where  the  sub-soil 
water  is  very  high.  Suakim  and  Massowa  are  also  said  to 
be  malarious,  but,  owing  to  the  character  of  the  fevers  in 
these  two  places,  it  is  doubtful  if  we  are  not  dealing  with 
dengue,  or  may  be  with  an  endemic  form  of  influenza. 

4.  Abyssinia. — Abyssinia,  which  is  situated  between  7°  oO' 
and  15°  30'  K  lat.,  and  between  35°  and  40°  E.  long.,  has  a 
mean  altitude  of  about  7000  feet.  It  is  an  extensive  table- 
land, from  which  mountains  rise  to  a  height  of  nearly  15,000 
feet.  The  highlands  are  mostly  covered  with  pasture  or  culti- 
vation, forests  being  rare.  The  climate  of  the  plains  varies 
with  altitude,  a  very  large  district  being  healthy  and  tem- 
perate, suited  even  to  European  colonisation.  The  mean 
annual  temperature  of  the  lowest  part  of  Abyssinia  is  about 
Q()°  F.,  and  the  rainy  season  begins  in  December  and  ends 
usually  in  March.  In  the  highlands  the  mean  annual  tem- 
perature varies  from  G7°  to  55°  R,  according  to  altitude. 
The  rainy  season  is  from  June  to  September,  the  rainfall 
being  about  40  inches. 

Diarrhoea,  dysentery,  and  rheumatism  are  very  prevaknt 


Tropical  Diseases  in  Africa.  23 

in  Abyssinia.  Small-pox,  for  which,  by  the  way,  inoculation 
is  employed,  is  exceedingly  prevalent,  as  also  is  syphilis,  and 
leprosy  is  fairly  common.  The  people,  too,  suffer  considerably 
from  worms,  this  being  due  to  their  custom  of  eating  raw 
meat.  Probably  phthisis  rarely  occurs  in  Abyssinia,  and 
diseases  of  the  chest  are  on  the  whole  infrequently  met  with. 
In  the  rainy  season  typhoid  fever,  relapsing  fever,  and 
epidemic  influenza  are  common.  The  natives  also  suffer  from 
scrofula  and  leprosy,  w^iich  is  especially  prevalent  in  the 
mountains,  and  goitre  is  said  to  occur.  Cholera  has  fre- 
quently visited  the  country.  Malarial  fevers  occur  in 
Abyssinia,  but  not  to  anything  like  the  extent  that  they  do 
in  other  parts  of  Africa.  There  are,  however,  a  considerable 
number  of  places  where  malaria  is  endemic. 

III.  Eastern  Africa. 

I  include  in  this  division  of  my  subject  the  country 
between  Cape  Guardafui  and  latitude  18°  N.,  and  the  coast 
inland  to  about  longitude  36°  E.;  also  the  island  of  Zanzibar, 
because  it  really  belongs  to  the  east  coast  of  Africa,  and 
the  conditions  which  obtain  there  are  practically  those  which 
are  found  on  the  coast. 

In  the  northern  part  of  this  area,  between  10°  N.  lat.  and 
the  equator,  we  find  the  Galla  and  Somali  districts.  Little  is 
known  of  them  from  a  climatological  and  medical  point  of 
view,  but  in  all  probability,  they  have  the  same  characteristics 
as  those  mentioned  when  referring  to  Abyssinia,  and  these 
regions  are  undoubtedly  healthier  than  any  on  the  east 
coast  farther  south,  if  we  except  the  highlands  between 
Kilimanjaro  and  Mount  Kenia  and  Lake  Victoria  Nyanza. 

From  the  equator  to  Delagoa  Bay  there  are  two  seasons — 
the  dry  season  from  June  till  October,  the  wet  one  from 
November  till  INI  ay,  the  greatest  rainfall  being  from  April 
to  June.  The  amount  of  rainfall  varies  in  different  localities 
from  1500  to  2500  mm.  The  mean  annual  temperature  is 
about  80°  F.  at  Zanzibar.  February  is  the  hottest  month, 
with  a  mean  temperature  of  about  84°  F. ;  July  the  coolest 
month,  with  a  mean  temperature  of  77°  F.  The  humidity  is 
very  marked. 


24  On  the  Geographical  Distribution  of 

The  inland  districts  of  the  east  coast  region  do  not  vary 
much  from  the  conditions  which  obtain  at  the  coast,  thouorh 
of  course  altitude  makes  itself  felt  in  modifying  those  con- 
ditions somewhat.  Thus,  around  Kilimanjaro  the  mean 
annual  temperature  may  be  said  to  be  slightly  higher  than 
at  Zanzibar,  mainly  about  85°  F.,  but  there  is  a  somewhat 
greater  range,  and  the  nightly  mean  is  probably  about  66°  F. 
Farther  south  in  the  Mpwapwa  district,  according  to  Pruen, 
the  maximum  daily  temperature  during  the  hot  season 
varies  from  80°  to  90°  F. ;  the  minimum  at  nights  is  65°  F. 
During  the  cold  season  the  daily  maximum  varies  from  70° 
to  80°  F.,  the  lowest  night  temperature  being  60°  F.  At 
Blantyre,  still  farther  south,  and  at  an  altitude  of  3000  feet, 
the  mean  annual  temperature  is  64°  F.  The  hottest  season 
is  during  October  and  November,  when  the  mean  temperature 
is  about  75°  F.,  the  coolest  season  being  June  and  July,  with 
a  temperature  of  about  60°  F.  The  rainfall  in  these  districts 
is  the  same  as  that  upon  the  coast,  the  smallest  precipitation 
being  near  Blantyre,  with  an  average  amount  of  58  inches, 
and  increasing  to  200  inches  in  the  north. 

The  east  coast  of  Africa  is  undoubtedly  very  unhealthy, 
and  on  the  coast,  and  with  few  exceptions  in  the  interior, 
emigrants  from  the  temperate  zone  cannot  thrive.  Practically, 
the  Shire  highlands,  the  slopes  of  Kilimanjaro  and  the  dis- 
tricts to  the  north-west  of  that  mountain  are  the  only  two 
areas  in  which  it  is  possible  to  think  of  white  races  colonising. 
The  diseases  which  do  not  occur  on  the  east  coast  are  scarlet 
fever,  phthisis,  and  goitre,  nor  is  cancer  met  with.  Whoop- 
ing-cough is  occasionally  known;  hepatitis  and  tropical 
abscesses  of  the  liver  are  less  frequently  met  with  than 
might  be  expected ;  measles  are  very  rare,  although  one  or 
two  serious  epidemics  have  occurred  in  the  southern  part  of 
the  district  under  consideration.  Both  the  anesthetic  and 
tubercular  forms  of  leprosy  are  occasionally  met  with. 
Cholera  has  visited  the  east  coast  of  Africa  on  several 
occasions  (Christie).  Kheumatism,  especially  the  chronic 
form,  is  met  with  all  over  this  area,  and  syphilis  and 
ophthalmia  are  very  prevalent.  Mcphantiasis  arahtnn  is 
also  seen,  but  not  extensively,  except  at  Zanzibar,  where  it 


Tropical  Diseases  in  Africa.  25 

is  very  common.  Tropical  ulcers  are  very  frequently  seen ; 
they  occur  chiefly  in  the  debilitated  natives,  and  cause  great 
havoc  in  the  slave  caravans.  Diarrhoea  prevails  extensively. 
Dysentery  is  extremely  common  throughout  the  whole  of  the 
area,  especially  at  Zanzibar.  Epidemics  of  dengue  are  of 
frequent  occurrence.  Although,  as  has  been  mentioned, 
plithisis  is  not  met  with  in  East  Africa,  yet  pleurisy  and 
bronchitis  are  very  common.  Typhoid  fever  is  fairly 
common.  Beri-beri  also  exists  in  East  Africa,  and  it  is 
probable  that  the  epidemic  dropsy  which  is  mentioned  by 
Livingstone  was  really  this  disease.  Throughout  all  East 
Africa  malarial  fevers  are  very  rife ;  they  are  most  severe 
upon  the  coast,  along  the  river  valleys,  and  in  marshy,  water- 
logged areas ;  in  fact  they  are  met  with  wherever  the 
factors  known  as  those  producing  malaria  exist.  To  these  I 
shall  refer  subsequently  when  dealing  with  the  prevention 
of  the  disease.  It  should  be  noted,  however,  that  the  fevers 
on  the  table-land  are  much  less  fatal  in  character  than  those 
met  with  upon  the  coast,  and  there  are  areas  over  2500  feet 
in  altitude,  where  it  may  be  said  that  the  incidence  of 
malaria  is  of  but  slight  import.  It  may  be  well  to  mention 
here  that  the  reason  why  East  Africa  has  such  an  evil  repute, 
owing  to  so  many  deaths  having  occurred  amongst  the 
Europeans  who  have  visited  it,  is  due  to  the  fact  that  these 
explorers  and  missionaries  have  been  compelled  to  make  a 
long  stay  on  the  coast  before  proceeding  inland,  and  have 
there  become  saturated,  as  it  were,  with  the  malarial  poison. 
Were  these  conditions  rectified,  and  were  it  possible  for  the 
whites  to  proceed  rapidly  to  the  interior,  there  is  no  doubt 
that  their  general  health  would  be  far  better,  and  it  is  for 
this  reason  that  for  the  last  ten  years  I  have  so  strongly 
advocated  the  construction  of  short  railways  to  carry 
travellers  rapidly  across  the  malarious  belt  on  the  coast. 

IV.  West  Coast  of  Africa. 

The  west  coast  of  Africa  from  Cape  Verd  to  Cape  Frio,  is 
the  hottest  and  wettest  region  in  the  globe,  probably  the 
most   unhealthy  too.      The   expression,   "the  white   man's 


26  0)1  the  Geographical  Distribution  of 

grave,"  which  is  given  to  this  part  of  Africa,  is  well. deserved. 
The  conditions  which  are  so  inimical  to  the  white  races  in 
this  region  are  continuous  heat,  excessive  moisture,  and 
sudden  changes  of  weather,  but  much  may  be  done  to 
render  the  climate  more  salubrious  by  sanitary  precautions. 
On  the  whole  coast,  probably  the  Cameroon  mountain  system 
is  the  only  place  of  sufficient  altitude  for  a  really  valuable 
health  resort,  but  the  Portuguese  portion  of  the  coast  is  not 
so  unhealthy  as  that  farther  north. 

A  rapid  summary  of  the  climatological  conditions  which 
obtain  in  the  various  regions  along  the  west  coast  must  now 
follow. 

First,  with  regard  to  the  coast  of  Senegambia.  The  mean 
annual  temperature  is  75°  F. ;  the  mean  diurnal  range  9°  F. 
The  average  rainfall  is  about  18  inches ;  the  average  humidity 
73.  The  hottest  months  are  June  to  November.  In  the 
interior  of  the  country  the  mean  annual  temperature  is 
about  83°  F.,  the  hottest  months  being  April,  May,  and  June. 
There  is  considerably  more  variation  in  the  temperature  in 
this  inland  region,  it  having  an  average  for  the  year  of  1 8°  F. 
At  Bathurst,  which  is  situated  on  St  Mary's  Island,  the 
chief  rains  fall  from  July  to  September,  about  39  inches 
falling  in  80  days.  At  Sierra  Leone  the  mean  annual 
temperature  is  82°  F. ;  the  rainfall  100  inches  in  August 
and  September.  On  the  Gold  Coast  at  Accra  the  mean 
annual  temperature  is  80°  F. ;  the  mean  range  about  7°  F. 
Humidity  is  very  high,  averaging  about  75  per  cent.  The 
rainfall  varies  considerably,  some  years  being  as  low  as  23 
inches,  in  others  nearly  40.  The  rainy  season  begins  at  the 
end  of  March  and  continues  to  June.  The  dry  season  is 
from  November  to  March. 

We  may  take  the  climate  of  Lagos,  still  farther  to  the 
east,  as  another  example  of  the  meteorology  of  Western 
Africa.  The  dry  season  obtains  from  the  beginning  of 
December  to  the  middle  of  March  ;  then  follow  the  heavy 
rains  until  the  middle  of  July  ;  from  then  till  September 
there  is  a  moderate  amount  of  rain  until  the  end  of 
November.  There  is  however  some  rainfall  during  each 
month,  but  only  about  1  inch  from  December  to  March. 


Tropical  Diseases  in  Africa.  27 

The  total  rainfall  is  about  58  inches  annually,  and  the  mean 
annual  temperature  80°  F.  The  mean  annual  variation  is 
very  slight,  being  only  about  10°, 

The  Niger  district  has  almost  the  same  characteristics  as 
the  one  just  mentioned,  except  that  the  temperature  is 
somewhat  higher,  the  heat  during  March  to  June  or  July 
averaging  105°  F.,  the  mean  annual  temperature  being 
about  86°  F.  The  rainfall  is  about  60  inches;  the  relative 
humidity  about  85.  Proceeding  farther  south,  we  come  to 
Gaboon,  where  the  mean  annual  temperature  is  95°  F.,  the 
rainfall  from  100  to  110  inches,  the  relative  humidity  very 
high,  rarely  under  90.  The  heaviest  rains  occur  between 
September  and  January. 

The  next  district  to  be  mentioned  is  that  at  the  mouth  of 
the  Congo.  The  mean  annual  temperature  is  76°  F.,  the 
annual  range  9°  F. ;  the  rainfall  43  inches ;  the  relative 
humidity  for  the  year  75  per  cent.,  the  annual  range  13. 
The  rainy  season  is  from  November  to  May,  with  prevailing 
westerly  winds. 

With  regard  to  the  next  region,  Angola,  the  following  data 
represent  the  climate  at  St  Paul  de  Loanda.  The  mean 
annual  temperature  74°  F.,  the  annual  range  12°  F. ;  the 
rainfall  13  inches ;  the  relative  humidity  82  per  cent.,  and 
the  annual  range  of  humidity  10.  Here  there  are  two  rainy 
seasons — October  to  December,  and  March  to  May. 

In  the  districts  to  the  south,  namely,  Benguela  and  Mosa- 
medes,  the  country  is  drier,  the  rainfall  varying  from  10  to 
30  inches,  the  mean  annual  temperature  being  about  68"  F., 
the  annual  range  20°  F. 

The  disorders  met  with  on  the  west  coast  of  Africa,  and 
which  may  be  regarded  as  the  most  prevalent  tropical 
diseases,  are  numerous,  and  we  have  to  deal  with  two  of  them 
which  are  unknown  on  the  eastern  side  of  the  continent, 
namely,  yellow  fever  and  yaws.  Following  the  rough  order 
which  I  have  hitherto  adopted,  we  find  that  typhoid  fever  is 
occasionally  met  with  in  Senegambia,  more  rarely,  perhaps,  in 
Sierra  Leone.  It  is  not  reported  from  the  Gold  Coast,  but  it 
occurs  in  the  Niger  district,  as  also  in  Gaboon.  There  are 
no  reports  of  typhoid  fever  from  the  Congo,  but,  as  it  is 


28  On  the  Geographical  Distribution  of 

stated  that  typho-malarial  fever  occurs  there,  in  all  prob- 
ability it  does  exist ;  for  as  I  shall  point  out  subsequently, 
I  am  convinced  that  typho-malarial  fever  does  not  exist  as 
a  disease  7:»cr  se,  but  that  in  all  cases  where  typho-malarial 
fever  is  reported  we  are  really  dealing  with  patients  in  whom 
both  typhoid  fever  and  malaria  are  present. 

Diarrhcea  and  dysentery  are  extremely  common  in  Sene- 
gambia,  being  most  frequently  seen  from  September  to  Nov- 
ember ;  also  prevalent  to  a  slightly  less  extent  in  December, 
January,  and  February.  Both  diseases  occur  also  in  endemic 
form  in  Sierra  Leone;  they  are  however  not  quite  so 
frequently  met  with  as  elsewhere.  Diarrhcea  is  often  met 
with  on  the  Gold  Coast,  but  dysentery  is  more  rarely  seen,  at 
any  rate  among  the  Europeans.  Both  diseases  occur  at 
Lagos,  as  also  with  extreme  frequency  in  the  Niger  district. 
Diarrhoea  is  very  common  at  Gaboon,  but  dysentery,  although 
endemic,  affects  the  natives  chiefly.  Probably  the  diminu- 
tion of  cases  amongst  the  white  residents  is  due  to  sanitary 
precautions.  On  the  Congo  coast  diarrhoea  prevails,  as  also 
dysentery,  but  this  disease  is  not  nearly  so  frequent  as  in  the 
Upper  Congo  district,  to  w^hich  reference  will  be  made  later 
on.  In  Angola,  diarrhoea  is  fairly  common,  but  dysentery 
is  more  rarely  seen,  and  when  it  occurs  it  is  chiefly  after  the 
rains. 

Severe  epidemics  of  dengue  occur  in  Senegambia,  but 
curiously  enough  that  is  the  only  place  on  the  west  coast 
of  Africa  where  this  disease  obtains.  Cholera  visited 
Senegambia  in  1868,  but  has  not  been  recorded  as  occurring 
elsewhere  on  the  west  coast  of  the  continent,  although  we 
do  find  scattered  notes  referring  to  sporadic  cholera  on  the 
northern  part  of  the  west  seaboard.  Now  in  1893  cholera 
is  again  ravaging  Senegambia. 

Beri-beri  is  very  prevalent  in  the  Congo  district  near  the 
coast,  as  also  is  a  disease  called  the  sleeping-sickness  or 
negro  lethargy,  a  disorder  which  has  a  rather  wider  distribu- 
tion, namely  from  Senegambia  to  this  district.  It  is  at 
present  a  moot  question  whether  these  two  diseases  are 
identical.  It  is  also  thought  by  some  that  both  diseases  are 
really  due  to  the  Anchylostoma  duodenalc,  and  if  so  they 


Tropical  Diseases  in  Africa. 


29 


would  be  identical  with  Egyptian  clilorosis,  which  is  un- 
doubtedly due  to  the  presence  of  that  worm. 

Yaws  or  framboesia  is  very  frequently  met  with  on  the 
west  coast  of  Africa,  from  Senegambia  on  the  north  as  far 
south  as  Angola. 

The  area  of  distribution  of  yellow  fever  is  at  present 
limited  in  Africa  to  the  west  coast  from  19°  K  to  a  point  on 
the  mainland  opposite  Fernando  Po. 

Hirsch  gives  the  following  chronological  survey  of  yellow 
fever  epidemics  on  the  west  coast  of  Africa  from  1816  : — 

Sierra  Leone,  Senegambia. 

Gambia  and  the  Congo 
coast  as  far  as  Angola. 

Gambia  and  the  Congo 
coast,  Gold  Coast,  Benin 
coast. 

Sierra  Leone. 

Sierra  Leone,  Congo  coast. 

Sierra  Leone,  Senegambia. 

Senegambia. 

Sierra  Leone,  Senegambia. 

Sierra  Leone  (?),  Sene- 
gambia. 

Diphtheria  and  scarlet  fever  are  unknown,  but  measles 
occurs  from  Senegambia  to  Angola.  Diseases  of  the  chest, 
such  as  bronchitis,  pleurisy,  and  pneumonia,  are  met  with 
all  along  the  coast,  but  phthisis  is  extremely  rare  among  the 
natives,  although  it  is  of  course  sometimes  seen  amongst 
the  whites,  who  have  in  all  probability  contracted  the 
disease  before  proceeding  to  the  coast.  Leprosy  is  frequently 
met  with  both  in  its  anaesthetic  and  tubercular  forms  in  the 
native  population  on  the  whole  of  the  West  African  coast. 
Syphilis  and  rheumatism,  especially  the  acute  form,  are  also 
extremely  prevalent. 

Elephantiasis  arabum  also  occurs  with  comparative  fre- 
quency over  the  whole  coast,  being  especially  prevalent  on 
the  Gold  Coast,  where  also  ainhum  is  frequently  seen. 

Small-pox  occurs  everywhere,  and  very  severe  epidemics 


1816.  Sierra     Leone,     Congo 

1859. 

coast. 

1860. 

1823.  Sierra  Leone. 

1825.  Sierra  Leone. 

1862. 

1829-30.   Sierra  Leone. 

1830.  Senegambia. 

1837-39.  Sierra  Leone. 

1864. 

1837.  Senegambia. 

1865. 

1845-47.  Sierra  Leone. 

1866. 

1852.  Gold  Coast. 

1867. 

1857.  Gold  Coast. 

1868, 

185S.  Senegambia. 

1878, 

30  Oil  the  Geographical  Distribution  of 

often  spread  with  extremely  fatal  results  amongst  the  native 
population.  Very  few  cases  of  cancer  are  met  with  on  the 
west  coast  of  Africa,  but  tropical  ulcers  are  extremely 
common. 

With  regard  to  hepatitis  and  tropical  abscess  of  the  liver, 
there  is  considerable  variation  in  the  occurrence  of  these 
diseases,  both  amongst  white  men  and  natives.  For  instance, 
hepatitis  is  extremely  prevalent  amongst  the  whites  in 
Senegambia,  but  is  not  often  seen  amongst  the  natives. 
It  is  comparatively  rare  in  the  Niger  district,  but  is  more 
frequently  met  with  on  the  Congo  coast.  On  the  whole, 
tropical  abscess  of  the  liver  is  less  frequently  seen  than  one 
would  expect,  and  it  would  appear  to  be  a  sequel  to  severe 
attacks  of  dysentery.  This  statement,  however,  should  be 
taken  with  caution,  as  if  it  is  true  it  is  very  different  from 
what  usually  obtains  in  India  and  other  tropical  countries. 
Whooping-cough  is  said  to  occur  in  Senegambia,  but  I  have 
seen  no  account  of  it  elsewhere. 

Amongst  the  native  population  over  the  whole  west 
coast  of  Africa,  skin  diseases  are  common.  Insanity  is 
not  frequent,  but  tetanus  often  occurs,  especially  amongst 
children.     Eickets  are  comparatively  rarely  seen. 

Anaemia  is  invariably  found  in  Europeans  throughout 
the  west  coast  of  Africa,  and  is  usually  due  to  malaria ;  it 
may  however  be  due  simply  to  residence  upon  the  coast. 
Guinea-worm  is  especially  frequent  between  Senegambia 
and  Cape  Lopez.  In  Senegambia  it  is  met  with  not 
only  on  the  coast,  but  in  the  more  elevated  region  which 
extends  from  Bakel  to  Galem,  though  the  parasite  does  not 
infest  the  banks  of  the  Casamance.  The  Sierra  Leone  coast 
is  less  extensively  infected  by  the  guinea-worm  than  the 
Grain  Coast,  Ivory  Coast,  Gold  and  Slave  Coasts.  The  worm 
is  met  with  throughout  the  Niger  district,  and  also  in  Gaboon. 

It  is  to  be  noticed  that  on  these  coasts  various  places,  such 
as  Cape  Coast  Castle,  Elmina,  Cormantia,  and  Accra,  are 
especially  affected,  whereas  the  surrounding  country  very 
often  is  free  from  the  parasite.  I  do  not  believe  that  there 
is  any  connection  between  guinea-worm  and  Elephantiasis 
arabian. 


Tropical  Diseases  in  Africa.  31 

Amongst  the  natives,  nervous  diseases  are  rather  frequently 
seen.  Hemiplegia,  paraplegia,  epilepsy  (especially  in  women), 
acute  mania,  and  dementia  are  met  with. 

Throughout  the  whole  coast  endemic  dropsy  occurs,  but 
here  again,  as  I  said  before  in  referring  to  the  east  coast,  I 
think  this  is  a  form  of  beri-beri.  Ague-cake  is  very  common, 
especially  in  Creoles.  It  is  said,  however,  to  be  un- 
common in  Sierra  Leone,  and  Gore  attributes  its  rarity  in 
that  region  to  the  ferruginous  character  of  the  soil.  Goitre 
is  not  frequently  seen  on  the  west  coast  of  Africa ;  there  are, 
however,  some  reports  of  its  occurrence  in  the  Cameroon 
district. 

The  west  coast  of  Africa  presents  four  seasons,  which 
generally  begin  and  end  as  follows,  allowing  for  latitude 
and  local  peculiarities.  The  summer  season  extends  from 
February  15  to  May  15,  the  rainy  season  from  May  15 
to  August  31,  the  harvest  season  from  September  1  to 
November  15,  while  the  harmattan  or  cold  season  begins 
on  November  15  and  ends  on  February  15. 

The  summer  is  hotter  than  any  of  the  other  seasons,  the 
heat  being  greatest  in  the  region  of  the  trade  winds,  and 
greater  in  Sierra  Leone  than  on  the  Gold  Coast  and  Bight  of 
Benin.  In  addition  to  the  prevailing  winds,  which  vary 
from  N.  and  N.E.  in  February  to  S.  and  S.W.  in  April, 
the  Gambia  region  is  subject  to  the  simoon,  a  hot  wind 
charged  with  fine  sand  which  blows  from  the  desert, 
destroying  vegetation  and  causing  much  distress,  especially 
to  those  suffering  from  respiratory  diseases.  Whirlwinds  are 
also  prevalent  during  this  season. 

The  rainy  season  is  ushered  in  by  a  cloudy  atmosphere 
and  frequent  tornadoes.  The  rain  gradually  increases  till  in 
July  and  August  it  descends  in  torrents,  in  many  places 
inundating  the  country  and  washing  away  huts  and  bridges. 
In  the  Gambia  region  the  commencement  of  the  rains  is 
marked  by  occasional  dirt  gales,  a  strong  wind  carrying  the 
surface  earth  along  with  it.  The  actual  rainfall  varies  in 
different  places,  and  also  in  the  same  place  from  year  to  year. 
It  is  greatest  during  the  night,  and  at  the  beginning  and 
end  of  the  season  the  fall  is  limited  to  the  night  time.     In 


:>2  0)1  the  Geographical  Distribution  of 

the  rainy  season  sand-flies  and   mosquitoes   are   especially 
troublesome. 

The  harvest  season  or  autumn  is  the  most  uuhealthy  part 
of  the  year  in  West  Africa.  The  rains  moderate,  the  swamps 
begin  to  dry,  while  the  decomposing  vegetable  matter  favours 
the  spread  of  malaria.  The  heat,  though  not  actually  so 
great  as  in  summer,  is  far  more  oppressive  from  the  moisture 
of  the  atmosphere.  The  south-west  monsoon  is  the  prevailing 
wind,  and  at  the  end  of  the  season  the  north-east  monsoon, 
while  beyond  the  region  of  the  "  trades  "  there  are  the  usual 
land  and  sea  breezes.  At  the  termination  of  the  harvest  the 
electrical  condition  of  the  atmosphere  is  much  disturbed,  this 
being  followed  by  the  cessation  of  rain  for  some  months. 

The  harmattan  or  cold  season  is  so  called  from  a  wind  of 
very  peculiar  character  which  occurs  at  this  time.  It  is  cold 
and  extremely  dry,  owing  to  its  course  from  the  east  over  the 
Sahara.  On  its  approach,  vegetation  of  every  kind  is  shrivelled 
up,  and  the  lips  and  eyes  of  those  exposed  to  it  suffer  from  its 
parching  effect.  It  is  accompanied  by  a  thick  fog  and  mist, 
composed  of  particles  of  fine  sand  of  the  desert.  It  only 
blows  for  a  few  days  in  the  season,  the  prevailing  wind  being 
from  the  south-east.  This  is  the  dryest  season  of  the  year, 
and  is  generally  healthy;  vegetable  matter  being  shrivelled 
instead  of  decomposed,  as  during  the  autumn,  does  not  favour 
the  production  of  malaria. 

The  months  of  February,  March,  April,  October,  and 
November  may  be  regarded  as  the  hot  season  of  West  Africa. 
During  this  period  the  increased  heat  gives  rise  to  certain 
physiological  effects  on  the  human  body.  The  temperature 
rises  to  100°  F.  or  even  102°  F.,  the  pulse  is  accelerated,  the 
respirations  diminish  in  depth  and  frequency,  the  urine 
becomes  concentrated,  and  activity  of  the  skin  is  enormously 
increased. 

Although  in  the  summer  season  the  heat  is  most  intense, 
it  is  not  so  unhealthy  as  the  autumn,  when  the  heat 
is  combined  with  moisture.  (The  month  of  October  is 
specially  unhealthy.)  The  heat  at  first  causes  an  exaltation 
of  general  sensibility,  but  afterwards  this  gives  way  to  marked 
depression. 


Tropical  Diseases  in  Africa.  33 

Exposure,  intemperance,  bodily  or  mental  depression,  may 
result  in  ardent  fever,  with  cerebral  or  hepatic  complications. 
Dysentery  and  diarrhoea  occur  chietiy  when  the  water-supply 
is  impure  from  storage  or  contamination  with  decaying  organic 
matter. 

The  chief  diseases  met  with  during  the  hot  season  are 
ophthalmia,  dysentery,  intermittent  fever,  rheumatism, 
leprosy,  guinea-worm,  and  prickly  heat. 

The  rainy  season  is  far  more  unhealthy  than  the  hot 
months,  especially  at  its  commencement,  and  to  a  less  extent 
at  its  close.  The  temperature  of  the  air  falls  at  the  beginning 
of  the  rains,  producing  a  feeling  of  vigour  after  the  intense 
heat;  but  the  moist  atmosphere,  combined  with  the  sun's 
rays,  greatly  increases  the  perspiration,  and  along  with  this 
there  is  relaxation  of  the  muscular  system,  with  cardiac 
debility  and  congestion  of  the  internal  organs.  Should  the 
rainfall  be  scanty,  irregular,  and  alternating  with  hot 
weather,  severe  outbreaks  of  fever  are  to  be  expected  from 
the  formation  of  pools  of  stagnant  water  rich  in  organic 
matter.  Dysentery  and  diarrhoea  are  also  prevalent  from 
the  contamination  of  the  water-supply;  while  in  addition  to 
the  diseases  mentioned  above,  diseases  of  the  respiratory 
system  are  also  met  with. 

It  is  likewise  to  be  noted  that  though  guinea-worm  may 
occur  at  any  season  of  the  year,  it  seems  to  be  more  trouble- 
some during  the  colder  months.  Elephantiasis  and  goitre 
also  seem  to  commence  more  frequently  in  the  cold  season, 
though  afterwards  the  seasonal  influence  on  their  progress  is 
less  marked. 

The  season  of  the  harmattan  is  the  most  healthy  part  of 
the  year,  the  drying  action  of  the  wind  stopping  the  decom- 
position of  vegetable  matter,  and  hence  the  production  of 
malaria.  When  it  begins,  patients  suffering  from  malaria 
rapidly  become  convalescent,  while  other  diseases  are  fre- 
quently benefited  in  like  manner.  The  dry,  cold  air,  while 
it  braces  up  the  body  generally,  reddens  the  skin  and  renders 
it  dry  and  harsh.  The  nostrils  and  pharynx  become  dry,  the 
lips  chap,  and  the  eyes  may  become  inflamed.  The  sensible 
perspiration  is  almost  arrested,  and  the  activity  of  the  kidneys 


34  On  the  Geof/i'ajyJiical  Distribution  of 

is  correspondingly  increased.  In  the  absence  of  free  renal 
secretion,  copious  diarrhoea  may  ensue,  and  may  persist  in 
spite  of  treatment  till  the  wind  abates.  The  other  diseases 
are  chiefly  the  result  of  the  internal  congestion  set  up  by  the 
cold,  congestion  going  on  to  sub-acute  inflammation  of  the 
liver  and  spleen,  ha3morrhages  from  mucous  membranes,  and 
abortion.  Infants  suffer  severely  from  cold  in  the  intervals 
between  the  harmattan.  Slight  attacks  of  fever  unattended 
by  prostration  may  occur ;  also  rheumatic  attacks,  but  these 
are  arrested  on  the  recurrence  of  the  desert  wind. 

According  to  Horton,  the  harmattan  has  a  decided  effect 
upon  small-pox ;  the  pustules  soon  heal  up,  and  the  disease 
disappears.  Persons  vaccinated  whilst  the  harmattan  wind 
is  blowing  are  not  protected  against  small-pox,  as  the  vaccine 
will  not  take. 

I  shall  now  deal  generally  with  the  incidence  of  malaria 
on  the  west  coast  of  Africa.  All  I  can  do  is  to  give  a 
summary,  which  I  hope  may  indicate,  with  some  attempt  at 
accuracy,  not  only  where  the  disease  is  prevalent,  but  where 
it  is  met  with  in  its  most  grave  forms. 

Some  amount  of  confusion  obtains  as  to  the  distribution  of 
the  graver  forms  of  malarial  fever  in  West  Africa.  This  is 
due  to  the  fact  that  some  observers  hold  bilious  remittent 
fever,  blackwater  fever,  endemic  hematuria,  and  typho- 
malarial  fever  to  be  distinct  diseases.  I  do  not  agree  with 
this  view,  and  in  what  follows  it  must  be  distinctly  understood 
that  I  entertain  the  conviction  that  these  so-called  various 
diseases  are  simply  malarial  fever  distinguished  by  some 
prominent  symptom  which  has  given  the  name  to  a  variety 
of  that  fever,  as  indicated  above.  Believing  as  I  do  that 
malaria  is  a  disease  swt  generis,  caused  by  the  ha^matozoon 
discovered  by  Laveran,  I  classify  the  results  of  its  action  on 
human  beings  as  follows: — Intermittent  fever  of  varying 
types  —  i.e.,  quotidian,  tertian,  quartan  ague ;  remittent 
malarial  fever,  including  bilious  remittent  fever,  blackwater 
fever,  haimoglobinuric  fever,  and  endemic  h;cniaturia ;  per- 
nicious malarial  fevers,  including  the  comatose  and  algid 
varieties ;    masked   malaria,   including   brow   ague   and    the 


Tropical  Diseases  in  Africa.  35 

various    neuralgias    couuected    with    malaria,    and    finally 
malarial  cachexia. 

To  the  causes  of  malaria,  and  its  production  being 
favoured  by  local  circumstances,  or  prevented  in  some 
cases,  I  shall  not  now  allude,  preferring  to  deal  with  such 
matters  later  on,  when  speaking  of  the  prevention  and  cure 
of  the  disease. 

Although,  as  before  mentioned,  the  West  African  coast  is 
called  "  the  white  man's  grave,"  yet  it  is  undoubtedly  true 
that  to  a  certain  extent  it  is  not  malaria  which  causes,  or 
perhaps  one  should  say  has  caused,  the  very  high  death-rate 
of  even  50  per  cent,  amongst  the  whites  on  the  coast.  In 
the  past,  at  any  rate,  this  death-rate  has  been  due  to  the  fact 
of  diseased  individuals  proceeding  to  Africa,  to  want  of 
knowledge  of  the  precautions  necessary  for  a  residence  there, 
and  unfortunately,  in  many  cases,  to  the  wilful  ignoring  of 
prophylactic  measures  and  of  a  well-ordered  life. 

In  Senegambia  malarial  fever  causes  at  least  40  per  cent, 
of  all  the  cases  of  disease.  In  some  places  the  admissions 
into  hospital  from  malarial  fever  rise  as  high  as  70  to 
80  per  cent.  The  greater  number  of  cases  occurs  during 
the  rainy  season,  or  between  June  and  November,  and 
chiefly,  in  all  likelihood,  at  the  commencement  and  at 
the  end  of  the  rains,  and  probably  the  pernicious,  and 
bilious  and  hsematuric  fevers  happen  chiefly  during  the 
rainy  season,  when  the  mean  monthly  temperature  is 
highest.  With  regard  to  the  hsematuric  fever,  it  probably 
occurs  only  under  certain  circumstances,  namely,  in  debili- 
tated individuals,  after  extreme  strain  or  excess,  or  after  a 
severe  wetting  following  repeated  attacks  of  ordinary 
intermittent  fever.  The  bilious  remittent  fever  may  be 
considered  as  an  acclimatising  fever,  occurring  chiefly  in 
newcomers. 

Next,  in  Sierra  Leone  the  amount  of  malaria  is  extreme. 
The  type  of  fever  is  here  very  severe,  a  very  fatal  remittent 
type  being  most  commonly  met  with  in  the  whites.  Again 
we  find  that  here  also  it  is  during  the  rainy  season  that 
malaria  is  most  virulent.  On  the  Gold  Coast  the  same 
conditions  exist,  and  grave  remittent  fevers,  with  bilious  and 


36  On  the  Geor/raphical  Distribution  of 

hfematuric  symptoms,  are  extremely  common,  as  also  are 
pernicious  fevers. 

Along  the  rest  of  the  coast  malaria  is  very  virulent  as  far 
as  Cape  Lopez.  Some  idea  of  its  prevalence  will  be  gained 
by  mentioning  the  death-rate  from  1878  to  1888.  Unfortu- 
nately, the  cause  of  death  is  not  stated  in  the  reports,  but 
malaria  appears  to  have  been  the  chief  cause. 

There  are  no  means  of  ascertaining  the  number  of  Europeans 
in  Gambia  during  the  years  in  question,  but  I  have  reason  to 
believe  there  were  about  54.  The  average  death-rate  there 
was  lOlO  per  cent.  At  Lagos,  from  1879  to  1888,  there  was 
an  average  of  110  European  residents ;  and  the  average  death- 
rate  was  10  per  cent.  At  Sierra  Leone,  the  population  during 
the  same  years  was  about  271,  of  whom  108  were  a  floating 
population,  i.e.,  belonging  to  ships  in  the  harbour.  The  total 
deaths  of  the  resident  population  were  44,  of  the  floating 
population  31,  giving  a  total  number  of  deaths  during  the 
ten  years  of  75,  being  42  per  cent.  On  the  Gold  Coast 
during  the  same  year  there  was  an  average  of  66  Government 
officials.  There  were  34  deaths,  the  average  death-rate  being 
51*43  per  thousand.  The  non-official  population  was  about 
126,  the  number  of  deaths  106,  the  death-rate  being  81*48  per 
thousand ;  or,  taking  the  officials  and  non-officials  together, 
the  death-rate  per  thousand  would  be  68*08,  the  average 
European  population  being  192. 

In  the  Niger  district,  remittent  fever  is  very  virulent,  and 
this  district  is  remarkable  for  the  prevalence  of  pernicious 
malarial  fever.  It  is  here  also  that  we  have  most  reported 
cases  of  so-called  typho-malarial  fever,  the  only  other  region 
where  this  complication  seems  to  prevail  being  the  Congo 
district;  at  Gaboon  and  in  its  near  proximity  malaria  is 
most  rife  during  the  first  three  months  of  the  year. 

In  the  Congo  coast  region  the  average  death-rate  from 
malarial  fever  appears  to  be  about  30  per  cent.  I  shall 
refer  to  its  prevalence  in  the  upper  regions  of  the  Congo 
subsequently. 

To  the  south  of  Loanda,  where  the  fever  is  very  rife, 
malaria  decreases  in  intensity  and  importance  as  we  proceed 
southward. 


Tropical  Diseases  in  Africa.  37 

V.  The  Sahara  and  Soudan. 

This  area,  which  includes  the  country  as  far  south  as 
10°  K  latitude,  takes  in  the  districts  of  Bornu,  Wadai, 
Darfur,  and  Kordofan,  and  must  be  dismissed  in  a  few  lines, 
statistics  being  wanting  with  respect  to  it.  On  the  whole 
the  climate  is  intensely  hot  in  summer,  but  the  diurnal 
variation  is  very  great.  Sometimes  the  thermometer  is 
many  degrees  below  freezing  point  at  night,  although  during 
the  day  it  may  be  as  much  as  115°  F.  In  the  northern  part 
of  this  district  the  mean  annual  variation  or  range  of  tem- 
perature is  from  40°  to  50°.  In  the  southern  part,  in  Wadai, 
Darfur,  Kordofan,  the  range  is  considerably  less,  being  only 
from  10°  to  20°  F.  Over  the  greater  part  of  the  area  the  mean 
annual  temperature  is  over  80°  F.,  although  in  the  district 
round  Wadai  it  varies  from  70°  to  80°,  this  being  due  to  the 
altitude  of  the  country,  which  is  from  3000  to  8000  feet.  On 
the  whole,  this  district  may  be  said  to  be  healthy.  Except 
in  the  oases,  malaria  is  almost  absent.  In  Darfur  and  Kor- 
dofan dysentery,  diarrhea,  and  typhoid  fever  are  met  with ; 
syphilis  and  bronchitis  are  fairly  common;  and  in  the  southern 
part  of  Darfur  the  guinea-worm  is  very  frequent,  the  area  of 
its  northern  distribution  at  this  point  being  about  11°  N. 
lat.  Goitre  is  not  infrequently  seen  in  inhabitants  of  the 
Djebel  Marra.  The  most  malarious  parts  of  this  district  are 
the  low  swampy  regions  round  Lake  Chad,  Dibbe,  and  Filter, 
and  the  province  of  Fezzan. 

VI.  Equatorial  Central  Africa, 

including  the  Congo  Free  State,  and  reaching  south  to  the 
18th  degree  of  S.  lat. 

The  mean  annual  temperature  of  the  whole  of  this  region 
is  about  78°  F.,  being  slightly  lower  to  the  west  of  the 
Victoria  Nyanza  in  the  Euwenzori  mountain  region,  on  the 
high  plateau  to  the  east  of  the  Victoria  Nyanza,  and  in 
Msiri's  kingdom,  where  it  varies  from  65°  to  70°  F.  The 
mean  annual  range  of  temperature  in  the  Congo  region  is 
less  than  5°  F. ;  in  the  remaining  area  it  is  between  5°  and 
10°  F.,  except  in  the  region  to  the  south  of  the  Victoria 


38  On  the  Geographical  Distribution  of 

Nyanza,  bounded  between  32°  and  38°  E.  long.,  where  the 
mean  variation  is  from  10°  to  20°  F.  The  mean  annual 
rainfall  is  about  50  inches,  except  in  the  centre  of  this  area, 
where  it  reaches  about  100  inches,  this  including  the  Congo 
forest  district  and  the  country  to  the  west  of  Tanganyika  as 
far  south  as  10°  S.  lat.  In  this  district  also  the  relative 
humidity  is  over  70  per  cent.,  but  over  the  whole  district  the 
relative  humidity  may  be  taken  as  about  66  to  68  per  cent. 

The  whole  region  is  highly  malarious,  but  I  will  give  a 
brief  account  of  malaria  as  I  met  with  it  in  Central  Africa. 
The  area  referred  to  extends  from  Khartoum  in  the  north  as 
far  south  as  the  Victoria  and  Albert  Lakes,  and  also  includes 
the  liohl  and  Bahr-el-Ghazel  districts.  The  distribution  of 
malaria  in  this  region  is  unequal,  and  the  topography  of  the 
country  exerts  an  influence  both  upon  its  frequency  and  its 
severity.  In  low-lying  swampy  regions  malaria  is  very 
common,  the  natives  suffering  to  a  considerable  extent  from 
mild  attacks  of  intermittent  fever.  Occasionally  one  sees  a 
case  of  well-marked  remittent,  but  perhaps  the  most  fre- 
quent variety  met  with  is  a  form  which  at  first  sight  appears 
to  be  a  continued  fever  lasting  from  five  to  seven  days.  But 
when  these  fevers  are  examined  carefully,  it  is  found  that 
they  are  really  either  mild  remittent  (for  there  are  distinct 
remissions,  which,  however,  must  be  carefully  looked  for)  or 
they  are  quotidian,  with  badly-marked  paroxysms.  A  very 
brief  cold  stage  occurs  daily,  then  follow  eighteen  or  twenty 
hours  of  hot  stage  with  a  temperature  of  102°-103°  F., 
followed  by  an  hour  or  so  of  apyrexia  after  a  very  slight 
perspiration.  Throughout  the  whole  region  the  natives,  who 
are  fairly  stationary  in  one  district,  suffer  comparatively 
little,  and  from  but  slight  attacks  of  intermittent  fever,  but 
if  removed  to  a  new  locality  they  suffer  from  much  more 
severe  attacks,  from  remittent  fever  for  the  most  part,  and  it 
is  a  noteworthy  fact  that  after  slave  raiding  or  war,  numbers 
of  men  are  struck  down  by  severe  forms  of  fever. 

In  the  higher  regions  the  fevers  become  more  rare  until 
one  reaches  districts  having  an  altitude  of  from  3000  to  4000 
feet,  where  they  almost  entirely  disappear.  A  good  example 
of  this  may  be  seen  in  the  country  to  the  north-west  of  the 


Tropical  Diseases  in  Africa.  39 

Albert  ISTyanza,  also  in  Central  Unyoro,  in  the  Shuli  district, 
to  the  south-east  of  Dufii,  and  in  Uganda,  in  the  Kahura 
district. 

With  regard  to  the  effect  of  malaria  u^^on  Europeans  and 
Egyptians,  one  notices  marked  differences;  and  here  the 
personal  equation  comes  notably  into  play.  Some  suffer 
very  little  from  malaria,  others  suffer  from  severe  remittents 
and  from  what  some  call  bilious  remittents  and  blackwater 
fever.  On  the  whole,  Europeans  suffer  less  from  anything 
more  than  an  occasional  attack  of  typical  intermittent  fever 
than  do  the  Egyptians.  Inactivity,  severe  marches  in  the 
sun  or  by  moonlight,  and  fatigue,  are  the  predisposing  causes 
of  attacks  of  fever  in  Europeans.  In  all  the  old  Egyptian 
stations  which  I  have  visited,  the  Egyptian  troops  and 
officials  suffered  excessively  from  malaria.  It  was  very 
fatal,  or  if  not  fatal,  it  induced  such  marked  debility  that 
they  were  greatly  incapacitated  for  ordinary  employment. 
I  found  that  the  "  spleen  test "  was  very  useful  in  ascertain- 
ing approximately  the  salubrity  of  a  district.  The  Bahr-el- 
Ghazel  district  is,  owing  to  its  very  abundant  water-supply 
and  its  many  swampy  areas,  excessively  malarious.  The 
country  to  the  north  of  the  Bahr-el-Arab  is  comparatively 
exempt. 

I  pass  on  now  to  deal  briefly  with  the  subject  of  enteric 
fever.  At  Khartoum  it  is  endemic,  and  no  wonder,  when 
one  considers  the  filthy  condition  of,  and  want  of  all  sanitary 
precautions  in  that  town,  and  the  quagmire  into  which  it  is 
yearly  transformed  at  high  Nile.  After  the  inundation  of 
the  Nile  the  disease  spreads  all  over  the  so-called  island  of 
Meroe.  In  all  the  districts  I  have  mentioned  above,  as  also 
in  Ivordofan,  I  met  with  cases  of  enteric  fever,  but  they 
varied  in  frequency,  not  so  much  with  the  character  of  the 
country  or  the  climatology,  as  with  the  habits  and  customs 
of  the  natives,  and  their  sanitary  surroundings.  The  disease 
was  most  frequently  seen  in  the  larger  settlements  in  the 
Bahr-el-Ghazel  districts.  There,  where  the  slave-dealers 
were  in  the  habit  of  crowding  together  thousands  of  slaves, 
the  filthy  condition  of  the  places  can  be  well  imagined,  and 
it  was  in  these  hotbeds  of  disease  that  I  saw  most  cases  of 


40  On  the  Geographical  Distribution  of 

enteric  fever.  Still,  I  met  with  the  disease  at  Bohr  on  the 
White  Nile,  at  Foweira,  at  Magungo,  just  to  the  north  of  the 
Albert  Nyanza,  and  1  witnessed  one  epidemic  in  Uganda.  I 
say  epidemic,  because  it  was  curious  to  notice  that,  generally 
speaking,  enteric  fever  seemed  to  stop  short  directly  an  area 
was  reached  in  which  the  banana  forms  the  staple  food  of 
the  population.  It  was  far  more  frequently  met  with  in 
those  districts  where  the  people  lived  chiefly  upon  grain. 

I  was  surprised  in  my  journey  in  Central  Africa  to  notice 
the  distribution  of  phthisis,  for,  although  bronchitis,  pleurisy, 
and  pneumonia  were  constantly  seen  in  nearly  all  the  dis- 
tricts through  which  I  passed,  the  cases  of  phthisis  which  I 
was  able  to  observe  were  few  and  far  between,  and  corre- 
sponded in  a  marked  manner  with  the  absence  of  malaria,  at 
any  rate  in  its  most  intense  forms.  From  Khartoum  along 
the  valley  of  the  Nile  as  far  as  the  Albert  Lake,  through  the 
swampy  districts  of  Unyoro  and  Uganda,  I  can  recall  having 
seen  very  few  cases  of  phthisis  (in  Uganda  some  eighteen 
or  twenty).  Subsequently,  however,  I  saw  a  considerable 
number  of  cases  in  the  Shuli  district,  at  an  altitude  of  3000 
to  4000  feet,  where  malaria  is  very  rare.  Again,  in  travel- 
ling through  the  Bahr-el-Ghazel  district  I  saw  a  considerable 
number  of  phthisical  individuals,  not  inhabitants  of  that 
province,  but  men  or  women,  soldiers  or  slaves,  who  had 
come  from  the  elevated  districts  in  the  !Monbuttu  country. 
Farther  north,  at  Dara,  I  again  met  with  phthisis  in  people 
who  inhabited  the  highlands  of  the  Djebel  Marra  district, 
where  I  was  informed  that  malarial  fevers  were  entirely 
absent. 

With  regard  to  the  other  diseases  of  Equatorial  Africa, 
what  follows  refers  to  the  districts  mentioned  above,  and 
with  which  I  am  personally  acquainted ;  but  from  what  I 
have  read  on  the  subject,  I  have  reason  to  believe  that  the 
same  diseases  obtain  to  the  south. 

Small-pox  occurs  in  epidemics,  and  is  very  fatal.  Measles 
and  scarlet  fever  are  unknown,  liheumatism  is  common 
everywhere,  and  cholera  has  on  various  occasions  passed 
through  the  country  in  the  form  of  epidemics.  With  regard 
to  phthisis,  it  is  very  rarely  met  with  throughout  the  whole 


Tropical  Diseases  in  Africa.  41 

of  the  northern  part  of  this  area,  except  in  the  high  region  to 
the  north-east  of  the  Victoria  Nyanza,  where  it  is  more 
common.  Diseases  of  the  chest  are  found  throughout  the 
whole  region,  but  bronchitis  is  far  more  common  than  either 
pleurisy  or  pneumonia.  A  form  of  plague  has  visited 
Uganda  on  several  occasions,  and  there  are  reports  of  it 
having  occurred  on  the  White  Nile  to  the  south  of  Lado  and 
in  the  Bahr-el-Ghazel  district.  Guinea-worm  is  most  pre- 
valent to  the  west  of  the  Nile  throughout  the  province  of 
Eohl  and  Bahr-el-Ghazel.  Eound  worms  are  also  met  with, 
and  Yaws  is  occasionally  seen.  Syphilis  is  widely  spread  in 
those  districts  where  the  slave  trade  has  been  carried  on,  but 
it  is  not  prevalent  in  other  regions.  Leprosy  is  met  with, 
but  not  extensively.  Elephantiasis  arahum  occurs,  especially 
on  the  west  of  the  Nile  to  the  south  of  Lado.  Skin  diseases 
are  extremely  frequent,  except  in  Uganda,  and  boils  are  of 
common  occurrence  everywhere. 

With  regard  to  nervous  diseases,  temporary  insanity  is 
often  met  with,  but  it  is  rare  to  see  cases  of  permanent 
aberration.  Epilepsy  is  fairly  common,  and  occurs  chiefly  in 
girls. 

Ophthalmia  is  comparatively  frequent,  although  it  is  not 
nearly  so  prevalent  as  in  Egypt.  With  regard  to  diarrhoea 
and  dysentery,  both  diseases  are  met  with  throughout  this 
region.  They  are  more  prevalent  throughout  the  Nile  valley, 
and  in  the  west,  than  in  Uganda  and  Unyoro.  The  so-called 
blackwater  fever  certainly  occurs,  and  so  does  typho-malarial 
fever,  but  in  all  cases  I  came  to  the  conclusion  that  these 
were  different  varieties  of  remittent  fever. 

Passing  now  to  the  Congo  region  of  Equatorial  Africa,  we 
find  that  malaria  is  prevalent  over  the  whole  of  the  district. 
All  varieties  occur,  from  mild  attacks  of  intermittent  fever 
lasting  three  days,  to  the  most  pernicious  forms  of  fever,  such 
as  are  seen  at  Vivi  and  Stanley  Pool.  It  is  said  that  the 
mortality  of  Europeans  in  the  Central  Congo  region  is  about 
25  per  cent.  Here,  too,  the  so-called  blackwater  fever  is 
common.  There  are  no  reports  of  enteric  fever  from  the 
Congo,  but  typho-malarial  fever  is  reported.  I  believe, 
however,  that  it  is  really  simple  severe  remittent  fever  with 


42  On  the  Geographical  Distribution  of 

typhoid  symptoms.  Dysentery  is  very  common,  and  so  is 
hepatitis,  and  tropical  abscess  of  the  liver  is  also  met  with. 
Phthisis  would  appear  to  be  rarely  seen,  if  at  all.  The 
ordinary  diseases  of  the  chest,  however,  occur;  as  also  do 
rheumatism  and  Egyptian  chlorosis.  Leprosy  and  yaws  are 
both  endemic  in  the  Congo  region,  as  also  the  disease  of 
sleeping-sickness,  as  it  is  termed  by  writers  from  this  region. 
As  previously  mentioned,  I  regard  this  disease  as  beri-beri. 

We  next  come  to  the  remaining  part  of  Equatorial  Africa, 
that  to  the  south  of  the  Victoria  Nyanza,  surrounding  Lakes 
Tanganyika  and  Nyassa,  as  far  south  as  the  Matabele 
country.  Throughout  this  region  malaria  is  again  exten- 
sively met  with,  except  in  the  highest  regions.  Enteric 
fever  exists  to  the  south  of  the  Victoria  Nyanza,  and  it 
appears  to  occur  occasionally  as  far  south  as  the  Zambesi. 
Both  diarrhoea  and  dysentery  are  found,  but  dysentery  is 
reported  to  be  exceedingly  severe  throughout  the  whole 
district,  far  more  frequent  in  fact  than  it  is  either  to  the 
north  or  west.  Eheumatism,  dengue,  leprosy,  and  syphilis 
are  all  prevalent,  and  so  are  the  ordinary  respiratory  diseases, 
but  phthisis  is  extremely  rare.  Elephantiasis  ardbum  is  met 
with  to  the  south-west  of  Tanganyika  especially,  but  isolated 
cases  are  occasionally  seen  throughout  the  whole  district. 
Tropical  ulcers  are  seen  very  frequently  in  this  district ;  so 
is  ophthalmia,  and  probably  beri-beri  is  widely  distributed. 
Curiously  enough,  diseases  of  the  liver  and  tropical  abscess 
are  rarely  seen  here.  Diphtheria  certainly  exists,  but  it  is 
not  very  prevalent. 

VII.  South  Africa, 

including  the  country  south  of  18°  S.  lat. 

The  area  with  which  we  have  now  to  deal  has  a  climate 
which  differs  much  from  any  we  have  hitherto  con- 
sidered; it  resembles  more  nearly  that  of  the  temperate  zone, 
in  which  zone  indeed  the  greater  part  of  the  district  lies. 
The  country  varies  considerably  in  altitude,  lying  generally 
from  GOO  to  10,000  feet  above  sea-level. 

The  mean  annual  temperature  varies  from  C-i"  to  7-°  F., 


Tropical  Diseases  in  Africa.  43 

excepting  in  the  Kalahari  Desert,  where  it  rises  to  about  76°  F. 
The  mean  annual  range  of  temperature  varies  somewhat :  on 
the  coast  it  is  from  10°  to  20°;  inland  it  is  from  20°  to 
40°  F.  The  annual  rainfall  varies  considerably.  It  is  least 
on  the  west,  where  it  is  under  10  inches;  indeed,  in  the 
north-west,  it  is  only  about  3  inches  annually.  On  the 
eastern  coast  the  precipitation  is  heavy,  varying  from  18  to 
40  inches.  Between  these  two  areas,  in  the  South  African 
Eepublic  and  Orange  Free  States,  the  annual  rainfall  is  from 
10  to  25  inches. 

In  the  most  northern  part  of  this  area  we  have  two 
districts — Mashonaland  and  Matabeleland.  The  altitude  of 
this  country  is  about  4000  feet.  The  rainy  season  is  from 
November  to  February,  and,  on  the  whole,  the  district 
appears  to  be  fairly  healthy,  although  we  have  not  sufficient 
reliable  information  upon  which  to  offer  a  final  opinion.  We 
know,  however,  that  dysentery,  diarrhoea,  and  rheumatism  are 
very  prevalent,  and  that  malaria  also  prevails,  though,  per- 
haps, not  so  extensively  as  it  does  to  the  north  of  the 
Zambesi, — e.g.,  Bechuanaland,  which  has  the  same  elevation. 
In  the  west  we  have  the  Kalahari  Desert,  with  a  very  slight 
rainfall  and  with  considerable  heat ;  but  the  eastern  district 
is  better  known,  and  therefore,  probably,  we  have  informa- 
tion of  more  numerous  diseases,  although,  on  the  whole,  the 
country  would  appear  to  be  healthy.  The  rainy  season  is 
from  December  to  April ;  the  average  rainfall  is  25  inches  ; 
the  temperature  may  be  as  high  as  85°  or  90°  F.  The 
climate  is,  on  the  whole,  dry  and  invigorating.  Probably 
the  most  fatal  disease  in  this  district  is  dysentery.  Enteric 
fever  is  also  met  with ;  malarial  fevers  are  unimportant ; 
measles  and  small-pox  occur  in  epidemics ;  phthisis  is 
unknown ;  bronchitis,  pleurisy,  and  pneumonia  are  only 
very  rarely  seen.  Syphilis  is  now  common ;  rheumatism 
and  hepatitis  are  both  met  with ;  ophthalmia  is  extremely 
common,  as  also  is  whooping-cough.  Leprosy  is  not 
endemic ;  this  is  rather  surprising,  as  the  disease  is  pre- 
valent at  the  Cape. 

The  Orange  Free  State  is  an  elevated  plateau  lying  4000 
to    5000   feet   above  sea-level.     It  possesses  a  remarkably 


44  On  the  Geograjjhical  Distribution  of 

dry  climate,  the  liumidity  being  about  55  per  cent.  During 
the  six  hottest  months  of  the  year  the  average  maximum 
temperature  is  82°  F.,  the  average  minimum  temperature 
55°  R  The  dust-storms  are  the  only  drawback  to  this 
climate.  The  average  maximum  temperature  for  the  six 
coldest  months  is  66°  F.  The  rainfall  is  16  inches. 
Diseases  of  the  chest  are  very  rare  in  this  district,  and  it 
forms  an  admirable  health  resort  for  phthisical  patients. 
Dysentery  and  diarrhoea  are  the  chief  diseases  to  be  dreaded 
here. 

The  Transvaal  has  the  same  altitude  as  the  Orange  Free 
State,  and  possesses  groups  of  mountains.  It  also  has  a 
dry  climate,  which  is  salubrious  and  exhilarating.  The 
rainy  season  lasts  from  October  to  March,  with  an  average 
rainfall  of  30-74  inches.  The  principal  diseases  in  this 
district  are  typhoid  fever,  dysentery,  and  diarrhoea.  Leprosy 
and  diphtheria  are  also  met  with ;  the  occurrence  of 
malaria  is  unimportant.  Owing  to  sudden  changes  in  the 
temperature,  bronchial  catarrh  is  fairly  common.  Phthisis 
is  not  seen. 

In  Natal,  including  Zululand,  Basutoland,  Griqualand  East, 
and  Pondoland,  the  climate  in  this  region  varies  consider- 
ably. At  Durban,  on  the  coast,  the  mean  annual  temperature 
is  77°  F.,  the  mean  range  18°  F.,  the  rainfall  is  33  inches. 
At  Pietermaritzburg  and  the  interior,  the  mean  annual 
temperature  is  68°  F.,  but  the  sudden  changes  from  hot,  dry 
land  winds  to  moist  sea  breezes  are  trying.  July  to  Septem- 
ber are  the  most  trying  months  in  Natal.  The  rainfall  at 
Pietermaritzburg  is  31-87  inches.  With  the  exception  of 
isolated  areas  at  the  coast,  and  in  some  of  the  gullies  in 
Zululand,  malaria  is  practically  unknown,  but  typhoid  fever 
and  dysentery  are  fairly  common,  as  also  is  diarrhcea  in 
the  hot  season,  llespiratory  diseases  are  very  rare,  but 
diphtheria,  small-pox,  measles,  and  scarlet  fever  sometimes 
occur  in  epidemics.  Phthisis,  except  in  imported  cases,  is 
practically  unknown. 

Cape  Colony  is,  on  the  whole,  very  healthy.  Temperature 
and  rainfall  vary  in  different  places.  At  Cape  Town  itself 
the  mean  annual  temperature  is  67°  F.,  the  annual  range 


Tropical  Diseases  in  Africa.  45 

38°  F.,  the  rainfall  2312  inches.  At  Port  Elizabeth  the 
rainfall  is  only  19-71  inches,  and  at  King  William's  Town, 
16-48  inches.  At  Graham's  Town  the  air  is  bright  and  ex- 
hilarating ;  the  mean  annual  temperature  is  G0°  F.,  mean 
annual  range  15°  F.,  rainfall  22  inches,  and,  occurring  as  it 
does  chiefly  in  summer,  it  keeps  down  the  temperature  and 
secures  remarkable  equilibrity.  In  this  region  malaria  may 
be  said  to  be  absent.  Again  here,  typhoid  fever,  dysentery, 
and  diarrhoea  are  the  most  frequent  and  fatal  diseases,  and 
rheumatism,  also,  is  very  prevalent.  Syphilis,  leprosy,  and 
scrofula  are  widely  prevalent,  but  respiratory  diseases  are 
unimportant.  Pneumonia,  however,  is  more  frequently  seen 
in  Cape  Colony  than  it  is  farther  north.  Phthisis,  owing  to 
the  number  of  imported  cases,  is  more  prevalent  than  one 
would  expect,  but  apart  from  this,  it  is  probable  that  the 
disease  does  exist  in  the  Colony  more  than  in  other  parts 
of  the  district  we  have  j  ust  had  under  review.  Scarlet  fever, 
diphtheria,  small-pox,  and  measles  occur  in  epidemics,  but 
infrequently.  Heart  disease  appears  to  be  specially  pre- 
valent. Cholera  has  never  visited  the  Cape,  and  hydrophobia 
is  unknown.  Diseases  of  a  parasitic  nature  are  rare,  and 
hydatids  are  infrequent. 

VIII.  Afkican  Islands. 

Madagascar,  the  largest  African  island,  is  situated  in  the 
Indian  Ocean,  between  12°  and  25°  S.  latitude.  It  can  be 
divided  into  a  low  coast-line,  and  extensive  highlands  having 
an  altitude  of  from  3000  to  4000  feet.  The  mean  annual 
temperature  of  the  coastal  region  is  between  74°  and  80°  F. ; 
the  mean  annual  temperature  of  the  highlands  is  64°  to  70°  F., 
the  mean  variation  between  5°  and  10°  F.  The  annual  rain- 
fall on  the  western  half  of  Madagascar  varies  from  25  to  50 
inches ;  on  the  eastern  half  it  varies  from  50  to  100  inches. 
At  Nossi  Be,  to  the  north-west  of  the  island,  it  is  over  100 
inches.  Malaria  is  most  prevalent  during  the  first  three 
months  of  the  year,  and  it  prevails  over  practically  the  vy^hole 
of  the  island.  It  is  especially  prevalent  on  the  coast,  and 
least  so  in  the  central  provinces.      Typhoid  fever  is  also 


46  0)1  the  Geof/rajyhical  Distribution  of 

prevalent  in  the  centre  of  the  island  ;•  dysentery,  on  the  other 
hand,  occurs  more  frequently  on  the  coast.  Diarrhoea  is  met 
with  all  over  the  island ;  phthisis  is  said  to  occur  in  the 
higher  regions,  but,  with  the  exception  of  pneumonia,  diseases 
of  the  chest  are  comparatively  rare.  Rheumatism,  leprosy, 
and  syphilis  are  common.  Beri-beri  occurs  in  epidemics; 
diseases  of  the  liver  are  fairly  common. 

The  Seychelle  Islands,  situated  between  3°  30'  and  5°  30'  S. 
latitude,  are  on  the  whole  healthy.  The  mean  annual  tem- 
perature is  about  77°  F.,  the  mean  annual  variation  about 
15°  F.,  and  the  mean  annual  rainfall  about  80  inches. 
Malaria  is  practically  unknown,  and  diseases  of  the  chest, 
with  the  exception  of  phthisis,  are  rare.  The  chief  diseases 
of  these  islands  are  dysentery,  phthisis,  and  affections  of  the 
liver.     Leprosy  and  syphilis  are  fairly  common. 

Mauritius,  an  island  lying  between  20°  and  20°  30'  S. 
latitude,  is  hilly,  and  has  an  elevation  of  from  500  to  700 
feet.  The  mean  annual  temperature  at  St  Louis  is  78°  F. 
April  to  November  is  the  coolest  part  of  the  year.  The 
rainfall  is  70  inches.  L^p  to  the  year  1866  the  island  was 
free  from  malaria,  but  since  then  it  has  been  very  malarious, 
both  intermittent  and  remittent  fevers  being  exceedingly 
frequent.  The  so-called  bilious  remittent  fever  is  very 
common,  and  typhoid  fever  is  also  frequently  met  with. 
Dengue  is  epidemic;  dysentery  and  diarrhoea  are  common, 
so  are  leprosy  and  syphilis ;  probably  also  beri-beri. 
Elephantiasis  arahum  is  endemic.  Chest  affections  are 
comparatively  rare ;  but  phthisis  is  sometimes  seen. 
Ophthalmia  is  exceedingly  prevalent,  and  hepatitis  seems 
general  amongst  the  white  population. 

The  foregoing  summary  of  the  climatology  of  the  various 
artificial  regions  into  which  I  have  divided  Africa,  and  the 
account  of  the  distribution  of  diseases  occurring  in  them, 
has  necessarily  been  somewhat  dry  and  tedious ;  indeed,  it 
has  been  very  difficult  to  compress  the  necessary  information 
within  at  all  reasonable  limits.  I  have  now  to  give  a  general 
statement  as  to  the  nature  of  the  prominent  diseases  met 
with  in  Africa,  their  cause  and  prevention,  and  the  methods 


Tropical  Diseases  in  Africa.  47 

of  treatment  which  are  employed  for  their  cure.  It  Avouhl 
of  course  require  a  volume  to  deal  with  the  subject  adequately, 
but  I  hope  I  shall  be  able  to  say  sufficient,  to  give  an 
intelligent  outline  of  the  subject. 

It  will  be  well  in  the  first  place,  to  describe  what 
methods  are  employed  by  the  natives  in  Africa  in  com- 
batting disease,  in  so  far  as  any  obtain,  and  then  to  describe 
the  methods  of  treating  disease  which  are  indicated  by 
modern  medicine. 

It  would  be  a  hopeless  task  were  I  to  attempt  to  describe 
in  detail  the  minutiae  of  medical  and  surgical  treatment 
adopted  by  the  natives  for  accident  and  disease  in  various 
parts  of  Africa,  nor  do  I  consider  it  necessary.  It  will  be 
better,  I  fancy,  to  give  a  more  general  outline  of  the  subject, 
but  it  is  very  necessary  to  state  that  I  am  doing  so,  for 
different  methods  obtain  among  different  tribes,  and  even 
neighbouring  tribes  may  have  different  ideas  and  customs 
with  regard  to  any  single  disease.  Were  I  not  to  state  this 
definitely,  I  should  easily  lay  myself  open  to  criticism  by 
any  observer  who  had  a  knowledge  of  one  single  tribe 
exclusively. 

The  natives  of  Africa,  and  by  these  I  mean  the  Negroes, 
Bantus,  and  the  Arabs  inhabiting  the  Soudan,  excluding  the 
Egyptians  and  the  inhabitants  along  the  northern  African 
coast,  have  many  superstitions  with  regard  to  medicine. 
Broadly  speaking,  one  may  say  that  the  questions  of  life  and 
death,  health,  and  sickness,  or  accident,  bulk  largely  in  their 
ethical  cogitations,  and  I  do  not  think  I  am  going  too  far 
when  I  say  that  the  natives  consider  that  all  the  evils  which 
flesh  is  heir  to  result  from  the  malign  influence  of  the  powers 
of  the  air.  So  they  have  pictured  to  themselves  gods  of 
small-pox  or  famine,  gods  of  thunder,  in  fact  a  hierarchy  of 
spirits  who  shape  the  destinies  of  men,  and  who  may  torment 
them  if  not  controlled  by  charms  or  propitiated  by  votive 
offerings.  Recognising  this  fact,  remembering  the  native 
suspicious  nature,  their  belief  in  fetishes  and  charms,  the  evil 
eye,  etc.,  it  is  not  to  be  wondered  at,  that  incantations  play 
a  marked  role  in  their  treatment  of  disease ;  but  it  is  a 
mistaken  notion  to  suppose  that  there  is  not  a  basis  of  true 


48  On  the  Geographical  Distribution  of 

common  sense  underlying  the  hocus-pocus  of  which  one 
hears  so  much  in  travellers'  tales.  The  natives  are  observant; 
they  recognise  the  fact  that  such  diseases  as  small-pox  and 
syphilis  are  contagious,  and  they  attempt  with  varying 
success  to  prevent  their  spread.  In  many  districts  in  Africa 
a  rigid  system  of  isolation  is  practised  with  regard  to  small- 
pox. The  patients  are  treated  in  a  hut  set  apart  for  the 
purpose,  they  are  attended  only  by  those  who  have  previously 
suffered  from  the  disease ;  a  definite  dietary  is  prescribed  for 
them,  simples  are  administered,  the  pustules  are  pricked  with 
a  sharp  thorn,  and  thereafter  various  unguents,  famed  for 
their  healing  properties,  are  applied  to  the  patient.  In  one 
district,  at  any  rate,  in  Africa,  inoculation  is  practised 
with  the  syphilitic  virus,  and  neither  young  man  nor  maid 
there  may  marry  until  they  have  been  through  the  inocula- 
tion ceremonies.  The  African  natives  have  a  considerable 
knowledge  of  the  virtues  of  plants.  Sudorifics,  diuretics, 
febrifuges,  purgatives,  and  emetics  are  known.  Numerous 
barks  and  plants  are  selected  as  possessing  these  various  pro- 
perties, and,  accompanied  by  incantations,  are  applied  with 
no  little  success.  The  actual  cautery  and  cupping  are  well- 
recognised  procedures,  and  are  employed  in  many  diseases. 

With  regard  to  surgical  operations,  amputations  are 
practised  iu  some  parts,  but  in  many  the  patients  would 
sooner  die  than  suffer  mutilation.  Splints  for  the  treatment 
of  fractures  are  known  and  widely  utilised  ;  luemorrhage  is 
stayed  in  various  ways,  either  by  cautery,  by  the  application 
of  boiling  oil  or  water,  or  of  compresses  composed  either  of 
astringent  herbs,  coffee  grounds  (in  the  Soudan),  or  cobwebs. 
It  is  when  dealing  with  such  diseases  as  epilepsy,  insanity, 
or  nervous  disorders,  that  the  natives  completely  fail, 
and  where  incantations  pure  and  simple  are  resorted  to. 
In  dealing  with  labours,  considerable  ingenuity  is  often 
manifested ;  turning  is  sometimes  practised ;  the  child  may 
be  expressed,  so  may  a  retained  placenta ;  in  dillicult  labours 
positional  treatment  is  in  vogue  iu  many  places,  and  in 
some,  even  abdominal  section  is  practised  with  more  or  less 
success. 

As  is  well  known,  poisons  and  their  antidotes  find  a  not 


Tropical  Diseases  in  Africa.  49 

unimportant  place  in  the  medicinal  lore  of  Africa.  At  least 
one  of  their  poisons — strophanthus — is  now  a  well-recognised 
medicine  for  heart  disease,  which  has  been  adopted  all  over 
the  civilised  world. 

What  medical  and  surgical  knowledge  the  natives  possess 
is,  as  has  been  indicated,  bound  up  with  witchcraft,  and  the 
knowledge  is  usually  handed  down  in  families ;  or  in  some 
cases,  as  for  instance  in  regard  to  poisons,  it  is  regarded  as  a 
tribal  secret,  and  the  method  of  preparation  of  poisous  and 
their  antidotes  is  only  communicated  to  such  as,  after  initia- 
tion, have  proved  themselves  worthy  to  be  the  recipients  of 
that  knowledge. 

Such  then  in  brief  is  the  character  of  the  native  methods 
of  treating  disease.  It  now  remains  for  me  to  indicate  what 
light  European  medicine  throws  upon  the  treatment  of 
disease  in  Africa,  and  how  far  modern  medicine  can  either 
prevent,  diminish,  or  cure  the  numerous  maladies  to  which 
white  races,  as  has  been  seen,  are  liable  when  transplanted 
to  this  foreign  soil. 

Certain  characteristics  should  be  possessed  by  individuals 
who  leave  a  temperate  climate  to  reside  in  Tropical  Africa. 
First  with  regard  to  temperament.  As  was  pointed  out  by 
Dr  Moore,  the  sanguine  temperament  is  associated  with  a 
tendency  to  congestive  affections,  to  a  rapid  and  irregular 
development  of  disease,  to  head  affections,  abscess  of  the 
liver,  and  scurvy. 

Persons  possessing  this  temperament  are  characterised  by 
active  muscular  systems,  and  high  animal  courage,  but  they 
live  at  high  pressure,  and  cannot  sustain  slight  exposure  to 
noxious  surrounding  influences.  The  nervous  temperament 
is  very  sensitive,  but  there  is  much  energy  and  capacity  for 
endurance  of  fatigue,  privation,  and  exposure;  persons,  how- 
ever, possessing  this  nervous  temperament,  are  prone  to 
diseases  of  the  nervous  system  and  hepatic  affections.  With 
regard  to  those  of  bilious  temperament,  the  frame  is  powerful 
and  the  person  possesses  great  endurance.  He  has  the  least 
sensibility  of  all  to  morbid  disturbances  and  external  impres- 
sions.    He  has  no  extraordinary  tendency  to  liver  affections, 

D 


50  On  the  Geographical  Distrihition  of 

except  in  the  extreme  form,  the  melancholic  bilious  tempera- 
ment. "The  bilious  temperament  possesses  the  good 
qualities  of  the  nervous,  without  its  irritability,  and  of  the 
sanguine,  without  its  susceptibility  to  external  impressions." 
Individuals  possessing  the  lymphatic  temperament  do  not 
resist  disease  well,  and  readily  suffer  from  disease  of  the 
liver  and  derangements  of  digestion.  It  follows,  therefore, 
that  the  bilious,  or  bilio-nervous  temperaments  are  best  fitted 
for  residence  in  the  Tropics ;  then  persons  of  the  sanguine 
temperament,  but  those  would  only  stand  the  climate  for  a 
short  time.  Persons  having  a  lymphatic  temperament  should 
stop  at  home.  No  one  possessing  a  syphilitic,  rheumatic, 
scorbutic,  or  malarious  history  should  go  to  the  Tropics,  and 
persons  either  suffering  from  or  having  a  tendency  to  heart 
disease  should  remain  at  home.  With  regard  to  age,  no  one 
should  go  to  Africa  under  the  age  of  twenty-five.  Persons 
under  this  age  are  bound  to  suffer  more  from  typhoid  fever, 
from  the  severer  forms  of  malarial  fever,  and  from  dysentery, 
than  those  who  are  older.  With  regard  to  women,  apart 
from  what  has  just  been  said,  no  woman  with  any  tendency 
to  the  diseases  special  to  her  sex  should  go  to  the  Tropics. 
With  regard  to  phthisis,  persons  who  have  only  incipient 
phthisis  will  do  well  in  North  and  South  Africa,  and  I  am 
not  at  all  sure  that  that  disease  should  be  a  bar  to  their 
proceeding  to  Tropical  Africa,  provided  that  they  are  not 
going  thither  with  the  object  of  undergoing  great  physical 
exertion. 

In  going  to  Africa  for  the  first  time,  it  is  well  to  arrive 
in  the  country  in  the  coolest  season.  That  season,  as  has 
been  seen,  varies  considerably  in  different  parts  of  the 
continent. 

It  is  not  my  intention  to  refer  to  the  diseases  which, 
though  occurring  in  Africa,  are  common  to  countries  in 
the  temperate  zone.  The  outstanding  diseases  to  which 
attention  must  be  directed  are  yellow  fever,  malaria, 
dysentery,  diarrhoea,  aud  typhoid  fever.  With  the  excep- 
tion of  yellow  fever,  all  these  may  be  said  to  be  prevalent 
throughout  the  continent.  I  will  proceed  to  deal  with  the 
less  important  diseases  first. 


Tropical  Diseases  in  Africa.  51 

Ainlium. 

This  is  a  peculiar  disease  affecting  the  Negro  race  of  both 
sexes.  It  always  occurs  in  the  small  toes  of  the  feet,  and 
is  diagnosed  from  leprosy  and  elephantiasis  by  there  being 
no  constitutional  disturbance.  The  origin  of  the  disease  is 
unknown;  it  commences  by  an  almost  semicircular  furrow 
in  the  digito-plantar  fold  on  the  internal  and  inferior  surface 
of  the  root  of  the  little  toe.  There  is  no  marked  inflammation 
or  ulceration.  The  toe,  however,  increases  in  bulk  until  it  is 
four  or  five  times  its  ordinary  size.  The  furrow  gradually 
deepens  until  the  toe  hangs  by  a  small  pedicle  to  the 
foot.  Sensibility  of  the  toe  is  not  lost.  The  treatment 
of  the  disease  consists  in  amputation,  after  which  it  is  not 
found  that  the  other  toes  become  affected. 

Beri-Beri. 

Beri-beri  is  a  disease  which  manifests  itself  in  ansemic 
or  debilitated  individuals ;  also  in  those  following  sedentary 
occupations.  It  is  never  met  with  in  people  until  they  have 
resided  in  the  country,  where  it  is  endemic,  for  about  a  year. 
It  is  a  fatal  disease,  death  taking  place  either  by  syncope  or 
from  embolism.  Its  cause  is  unknown;  there  are,  however, 
two  theories  in  regard  to  it.  The  one  is,  that  it  is  due  to 
water  impregnated  by  saline  material,  and  the  other  that  it  is 
akin  to  Egyptian  chlorosis  {q.v.),  and  that  water  conveys  to 
the  individual  the  larvoe  of  the  Anchylostmnum  duodcnale. 
I  incline  to  the  former  theory. 

It  has  long  been  thought  that  a  specific  micro-organism 
must  cause  beri-beri,  and  two  observers — Drs  Mosso  and 
Morelli — have  examined  the  blood  of  eleven  patients  suffering 
from  the  disease,  with  uniform  results.  When  rabbits  and 
guinea-pigs  were  inoculated  with  cultures  made  from  the 
micro-organisms  of  the  blood,  the  animals  apparently  died 
from  beri-beri,  and  after  death  three  prominent  conditions 
were  found — ascites,  hydroperi  cardium,  and  nephritis.  The 
liquid  found  in  the  abdomen  and  pericardium  was  strongly 
albuminous,  and  contained  salts — corresponding,  therefore,  in 


52  On  the  Geographical  Distribution  of 

general  characteristics  with  the  fluids  found  in  the  bodies  of 
human  beings  suffering  from  beri-beri. 

The  symptoms  are  extreme  weakness  and  prostration, 
dyspncea  and  palpitation  on  exertion,  numbness  of  the 
lower  extremities,  followed  by  cedema,  anesthesia,  and,  more 
rarely,  by  paralysis.  The  oedema  gradually  pervades  the  whole 
body,  and  effusions  take  place  within  the  cranium,  pleura, 
or  pericardium.  Pari  passu  with  the  increase  of  the  dropsy, 
the  whole  body  becomes  numb.  The  urine  is  high-coloured 
and  scanty,  the  specific  gravity  1030  to  1040,  and  acid.  It 
may  be  suppressed.  Constipation  is  usually  present.  Con- 
siderable pain  is  often  experienced  in  the  cardiac  region,  and 
the  pulse  is  irregular,  unless  effusion  takes  place  within  the 
cranium,  when  headache  and  delirium  are  frequent,  and  the 
pulse  is  slow  and  full.  The  prognosis  is  good  if  the  disease 
occurs  in  young  and  otherwise  healthy  individuals,  but  the 
mortality  on  the  whole  is  about  30  per  cent. 

The  treatment  consists  in  the  use  of  iron,  nux  vomica  and 
diuretics,  and  a  stimulating  nutritious  diet.  In  India,  Treeak 
farook  is  used  with  advantage.  Frictions  with  rubefacient 
liniments  are  useful;  petroleum,  externally  and  internally, 
has  been  advised  by  S.  Arokeum.  The  only  preventive 
measure  which  can  be  recommended,  apart  from  the  ordinary 
precautions,  is  to  ensure  a  good  water-supply. 

Bilharzia  Hematuria. 

This  disease  is  caused  by  the  ingestion  of  water  containing 
the  embryos  of  the  Bilharzia  hcvmatoUa,  or  possibly  by 
bathing  in  water  infested  by  them.  It  causes  hematuria, 
cystitis,  pyelitis,  and  sometimes  dysentery.  It  is  chiefly  met 
with  in  Egypt  and  at  the  Cape  of  Good  Hope. 

It  is  quite  possible  that  some  minute  leech-like  animal 
fixes  itself  on  the  skin  of  the  bather,  and  by  means  of  an 
ovipositor  implants  the  ova  in  some  superficial  cutaneous 
vein,  and  then  the  free  embryos  might  be  carried  by  the 
circulation  from  the  ankle  or  leg  to  the  pelvis.  Persons  who 
use  river  water,  or  water  from  pools  or  marshes,  are  most 
frequently  attacked  by  the  disease,  those  who  use  stored 


Tropical  Diseases  in  Africa.  53 

rain  or  well  water  being  rarely  affected.  On  examining  the 
urine  in  these  cases,  it  will  be  found  to  deposit  a  layer 
of  dirtyish  white  flocculent  matter  containing  short  filaments 
of  135th  of  an  inch  in  diameter,  of  a  brownish  colour  and 
soft  consistence.  Microscopically,  pus  corpuscles  are  seen, 
and  filamentous  bodies  containing  great  numbers  of  bright, 
highly  refractive  bodies  imbedded  in  them.  These  bodies 
are  the  ova  of  the  bilharzia.  Stone  in  the  bladder  is  not 
infrequently  caused  by  the  ova;  the  ova  in  the  bladder 
become  imbedded  in  a  plug  of  hard  mucus,  and  so  form 
the  nucleus  of  a  stone. 

Prophylactic  Treatment — After  bathing  in  districts  where 
this  disease  prevails,  the  skin  should  be  thoroughly  and 
very  vigorously  rubbed  with  a  very  rough  towel.  Filter 
and  boil  all  drinking  water.  All  raw  salads  and  molluscous 
animals  ought  to  be  excluded  from  the  diet.  It  is  also 
essential  to  remove  persons  from  the  locality  in  which  it  is 
believed  they  have  contracted  the  disease. 

Treatment. — The  patient  must  be  well  fed,  must  take 
moderate  exercise,  use  cold  baths  and  take  tonics,  either  the 
mineral  acids  or  the  citrate  of  iron  and  quinine.  Vesicle 
irritation  must  be  subdued  by  the  use  of  bicarbonate  of 
potash  and  infusion  of  buchu.  Haimorrhage  may  be  checked 
by  uva  ursi  combined  with  small  quantities  of  hyoscyamus, 
or  hamamelis  is  very  useful.  Sometimes  the  injection  of 
iodide  of  potassium,  3  to  5  grains  to  the  ounce  of  water — 
and  retention  in  the  bladder  for  three  hours — is  beneficial. 
If  the  kidneys  are  affected,  quassia,  or  the  extract  of 
male  fern,  should  be  administered.  It  is  possible  also 
that  the  following  prescription  may  be  given  three  times 
a  day  with  advantage, — 

R.  Bicarbonate  of  soda,  15  grs. 
Chian  turpentine,  10  grs. 
Acacia  mixture,  2  drs. 
Chloroform  water  to  1  oz. 

to  which  opium  may  be  added  if  there  is  much  pain  or 
irritation  in  the  urinary  passages. 


54  On  the  Geographical  Distribution  of 

Delhi  Boil,  or  Oriental  Sore,  or  Biskra  Button, 
or  African  Date-Mark. 

This  disease  begins  by  itching,  usually  of  some  surface  on 
the  exposed  part  of  the  body.  A  papule  is  then  formed, 
which  soon  becomes  pustular.  The  discharge  from  the 
pustule  forms  crusts,  under  which  ulceration  goes  on.  The 
sore  lasts  for  about  five  or  six  months,  leaving  deep  dark 
cicatrices,  hence  the  name  date-mark.  It  is  inoculable,  and 
occurs  at  all  ages.  It  is  not  accompanied  by  pain  or  fever. 
It  is  usually  single,  but  may  appear  in  crops.  Although  it 
is  certainly  a  specific  affection,  it  is  as  yet  impossible  to 
determine  its  cause.  It  does  not  appear  to  be  due  to  water, 
or  to  climate,  or  to  eating  fresh  dates.  Some  believe  (Carter) 
it  is  due  to  a  mycelium  arranged  in  open  and  angular  meshes 
with  conidia  on  its  free  ends,  having  subsequently  bright 
orange-tinted  particles  arranged  in  spherical  or  ovoid  groups, 
supposed  to  be  a  further  stage  of  development.  It  is  met 
with  in  horses  and  dogs. 

Preventive  Treatment. — The  use  of  pure  filtered  water,  good 
food,  absolute  cleanliness  of  house,  clothes,  and  person, 
avoidance  of  overcrowding,  and  contact  with  the  disease  in 
animals  or  human  beings,  with  careful  attention  to  sanitary 
surroundings,  are  the  only  means  which  can  be  suggested 
as  prophylactic  to  the  disease.  The  local  treatment  shouhl 
be  water-dressings,  followed  by  linseed-meal  or  bread 
poultices ;  but  when  the  ulcer  is  formed,  a  stringent  lotion, 
such  as  sulphate  of  iron,  carbolic  acid,  and  iodine  may  be 
applied.  If  the  patient  suffer  from  malaria,  quinine  must  be 
given.  If  a  scorbutic  taint  is  suspected,  fresh  vegetables  and 
lime  juice,  or  fresh  lemon  juice  are  advisable;  or  should  a 
syphilitic  taint  be  made  out,  small  doses  of  mercury  and  iodide 
of  potassium  will  be  of  use.  In  all  cases  a  tonic  regimen 
should  be  followed.  Change  of  air  and  of  drinking  water  is 
most  desirable,  and  a  voyage  home  may  be  needful  in  obstinate 
cases. 

Dengue. 

Dengue  may  be  described  as  a  specific  fever,  characterised 
by  a  high  temperature,  a  peculiar  and  distinctive  rash,  violent 


Tropical  Diseases  in  Africa.  55 

and  acute  pains  in  the  head  and  eyes,  the  muscles  and  joints  ; 
there  is  swelling  of  the  joints,  and  the  pains  are  apt  to  shift 
suddenly  from  one  limb  or  joint  to  another;  the  throat  and 
mouth  are  often  affected,  as  well  as  the  sub-maxillary  glands ; 
the  sensorium  is  often  much  disturbed,  and  active,  violent 
delirium  is  not  uncommon.  The  disease  is  very  infectious, 
and  attacks  persons  of  every  age  and  sex.  It  may  remit, 
and  is  liable  to  relapse.  Some  authorities  consider  that 
dengue  is  intimately  connected  with  relapsing  fever.  Dr 
Christie  thought  that  it  was  related  to  cholera.  Although 
the  complications  of  dengue  are  very  troublesome,  yet  the 
prognosis  is  favourable.  Deaths  usually  occur  from  syncope 
in  children,  in  the  aged,  and  in  the  debilitated.  Summer 
and  early  autumn  are  the  seasons  when  dengue  is  most 
prevalent.  All  epidemics  have  occurred  during  the  hottest 
weather.  It  does  not  appear  that  the  amount  of  moisture 
in  the  air  has  anything  to  do  with  its  production. 
The  onset  of  the  disease  is  sudden.  After  suffering  from 
severe  rigors,  the  patient's  temperature  runs  up  to  103°  or 
104°  F.  Headache,  pains  in  the  joints,  and  nausea  are 
prominent  symptoms.  The  patient  is  sleepless  and  restless. 
Enlargement  of  the  lymphatic  glands  is  noticed.  There  may 
be  epistaxis,  salivation,  diarrhoea,  or  dysentery.  Hepatic 
derangements  are  sometimes  seen.  Women  may  suffer 
from  uterine  haemorrhage,  and  if  pregnant  are  liable  to  mis- 
carriage. The  first  eruption,  which  appears  on  the  third  day, 
resembles  that  of  scarlet  fever,  the  throat  being  likewise 
affected.  After  two  or  three  days  the  fever  subsides,  and  the 
rash  disappears,  but  after  an  interval  of  from  24  to  36  hours 
the  fever  returns,  accompanied  by  a  secondary  rash  re- 
sembling measles. 

With  regard  to  prophylactic  treatment,  no  drug  is  of  any 
service,  but  overcrowding  and  faulty  sanitation  appear  to 
favour  the  spread  of  the  disease.  The  greatest  care  should 
be  taken  in  thoroughly  disinfecting  all  fomites,  for  contagion 
may  persist  a  long  time,  and  the  dead  should  be  carefully 
disposed  of. 

General  Treatment. — Castor-oil,  or  some  warm  carminative 
aperient,  should  be  given  at  the  onset  of  the  disease,  violent 


56  On  the  Geographical  Distribution  of 

purgatives  being  contra-indicated.  Then  the  following 
effervescing  draught  is  useful, — 

R.   Bicarbonate  of  potash,  2  drs. 
Tinct.  opium,  ^  dr. 
Syrup  of  orange,  6  drs. 
Camphor  water  to  6  ozs. 

Half  an  ounce,  with  a  tablespoonful  of  lime  juice  ad- 
ministered whilst  effervescing,  every  three  or  four  hours. 

For  the  restlessness,  20  or  30  drops  of  chloric  ether  may 
be  given  with  each  dose,  or  saline,  such  as  acetate  of 
ammonia,  or  citrate  of  potash,  with  nitrous  ether,  may  be 
useful  during  the  pyrexia.  If  the  temperature  rises  above 
105°  R,  the  patient  should  be  sponged  with  cold  water.  If 
the  pain  is  very  severe,  10  or  15  drops  of  the  tincture  of 
belladonna  should  be  given  every  three  or  four  hours.  Opium 
or  cliloral,  or  Dover's  powder  in  moderate  doses,  are  some- 
times useful  at  bedtime.  The  eruption  should  be  treated 
with  simple  bismuth  ointment.  Warm  baths,  in  which  a 
couple  of  pounds  of  bicarbonate  of  soda  have  been  dissolved, 
are  also  beneficial.  Liniments  containing  opium,  belladonna, 
and  chloroform  may  be  applied  to  the  spine  and  joints. 
After  the  first  remission  the  following  prescription  should 
be  given, — 

R.   Carbonate  of  potash,  1  dr. 
Nitrate  of  potash,  1  dr. 
Tincture  of  orange,  3  drs. 
Water  to  6  ozs. 

1  oz.  every  three  hours,  and  quinine  5  to  8  grs.  should  be 
administered  thrice  daily.  For  convulsions  in  children, 
bromide  of  potassium  may  be  given.  In  adults,  if  there  be 
great  depression  or  marked  nervous  symptoms  during  con- 
valescence, dilute  phosphoric  acid  with  nux  vomica,  or  small 
doses  of  strychnine,  should  be  employed.  The  enlarged 
lymphatic  glands  may  give  trouble  during  convalescence  ; 
they  should  be  painted  with  strong  iodine  paint,  and  small 
doses  of  iodide  of  potassium  should  be  given  internally.  The 
rheumatic  pains  are  apt  to  persist,  and  it  may  be  necessary 


Tropical  Diseases  in  Africa.  57 

to  blister  the  surface,  and  dress  the  blister  with  morphia ; 
and  if  the  internal  administration  of  belladonna  does  not 
succeed  in  controlling  the  pain,  the  following  prescription 
should  be  tried, — 

R.  Nitrate  of  potash,  40  grs. 
Spirits  of  sweet  nitre,  2  drs. 
Colchicum  wine,  2  drs. 
Water  to  8  oza. 

1  oz.  thrice  daily. 

Guinea-  Worm. 
{Filaria  Medinensis ;  Dracunculus  Meclinensis.) 

The  guinea-worm  is  a  nematoid  worm,  the  female  only  of 
which  is  known.  It  is  about  1  mm.  thick,  and  has  an  average 
of  2  feet  in  length  ;  it  may,  however,  be  much  longer.  It  is 
cylindrical ;  the  anterior  extremity  is  rounded,  and  presents 
a  small  depression  surrounded  by  an  elliptical  chitinous 
plate,  at  the  margin  of  which  are  two  papilla3.  The  posterior 
end  is  a  short  curved  point ;  it  is  opaque,  of  a  milk-white 
colour,  and  on  each  side  there  is  a  longitudinal  line.  The 
interior  of  the  worm  contains  an  immense  number  of  young 
filarife  in  an  acrid  secretion.  The  tenacity  of  the  tissue  of 
the  guinea-worm  is  considerable,  so  that  a  loop  of  the 
parasite  will  support  the  weight  of  10  oz. 

The  largest  number  of  persons  becomes  infested  with  this 
worm  at  the  end  of  the  rainy  season,  or  in  the  hot  season  after- 
wards. The  guinea-worm  attacks  all  races  and  nationalities, 
both  sexes,  and  at  all  periods  of  life.  Usually  only  one  or 
two  worms  are  found  in  the  patient,  but  I  once  saw  one  with 
no  less  than  forty-two  worms.  It  is  said  to  gain  an  entrance 
into  the  body  by  means  of  drinking  water,  but  this  is  doubtful. 
So  far  as  I  know,  there  is  no  case  on  record  in  which  the  worm 
has  been  found  within  the  abdomen.  It  is  in  all  probability 
deposited  beneath  the  skin,  and  this  theory  is  supported  by 
the  fact  that  it  only  occurs  in  those  who  walk  bare-footed 
either  constantly  or  occasionally,  that  it  principally  occurs  in 
the  lower  extremities,  that  in  those  cases  in  which  it  occurs 
on  the  trunk  or  arms  it  is  in  persons  who  have  slept  on  the 


58  On  the  Geof/rcqihical  Distribution  of 

ground,  or  who  have  carried  earth  or  water.  In  1190  cases 
I  saw,  the  feet  were  affected  in  556  cases,  the  legs  in  274, 
the  thighs  in  104,  the  scrotum  in  4,  the  penis  in  3,  labia 
majora  in  3,  abdominal  walls  in  1,  the  breast  in  2,  the  back 
in  143.  I  never  myself  saw  it  in  the  head,  arms,  or  else- 
where. The  average  time  of  incubation  after  the  ova  is 
deposited  within  the  skin  appears  to  be  from  three  to  six 
months.  It  is  only  when  the  worm  arrives  at  maturity  that 
the  patient  first  becomes  really  aware  that  he  has  contracted 
the  disease.  He  suffers  from  a  severe  attack  of  fever,  the 
stomach  becomes  irritable,  bilious  vomiting  takes  place,  and 
attention  is  now  first  attracted  to  the  situation  of  the  guinea- 
worm.  Intense  itching  is  felt,  w4th  a  sensation  of  a  thin 
cord  underneath  the  skin ;  occasionally  also  a  small  pimple 
or  blister  can  be  seen,  and  when  this  occurs  in  a  district 
infested  by  the  guinea-worm,  it  may  generally  be  regarded 
as  a  sufficiently  diagnostic  sign,  especially  if  accompanied  by 
any  swelling. 

The  development  of  this  characteristic  blister  or  vesicle 
always  coincides  with  the  advance  of  the  worm  to  the  surface 
of  the  body.  The  blister  may  sometimes  be  as  large  as  half  a 
walnut,  and  may  be  attended  also  by  an  eruption  resembling 
nettlerash.  "When  this  vesicle  is  opened,  it  is  seen  to  be  filled 
with  either  a  glary,  whitish  fluid,  or  with  the  reticular  portions 
of  the  true  skin,  the  areola  being  a  meshwork  filled  with  serum, 
at  the  centre  of  which  a  small  aperture  is  visible,  in  which 
the  extremity  of  the  worm  will  be  found.  As  the  worm 
protrudes  from  the  skin,  it  should  be  secured  to  a  small  piece 
of  twig  or  crowquill  and  gradually  withdrawn.  Great  care 
must  be  taken  not  to  break  the  worm,  as  if  it  is  broken 
extensive  and  destructive  inflammation  in  the  connective 
tissue  occurs.  The  prognosis  in  general  is  good  if  the  case 
be  treated  carefully,  but  it  may  cause  distortions  of  the  lower 
extremity,  such  as  talipes  equinus,  permanent  enlargement  of 
the  internal  maleolus,  permanent  contraction  of  the  leg  or 
the  tliigh,  and  sometimes  permanent  anchylosis  of  the  knee 
joint,  or  gangrene  of  either  toe,  foot,  or  leg. 

Prevrntivc  Treatment. — Never  walk  bare-footed  in  a  region 
where  the  worm  is  endemic ;    do  not  bathe  in  muddy  pools. 


Tropical  Diseases  in  Africa.  59 

After  walking  through  swamps,  see  that  the  skm  is  well 
rubbed  with  a  rough  towel  or  flesh  brush.  All  drinking 
water  must  be  filtered. 

Internal  Treatment. — Nitrate  of  potash  in  2  dr.  doses  given 
in  butter-milk  is  said  to  cure  guinea-worm  in  from  three  to 
five  days,  and  the  application  of  electricity  to  the  worm- 
affected  part  may  cause  its  death.  Asafoetida  in  5  to  15  gr. 
doses  daily  for  a  week  has  cured  many  cases.  It  is  said  also 
that  feeding  a  patient  on  sugar-candy  for  twenty-four  hours, 
without  any  other  food  or  drink,  may  cause  the  death  of  the 
worm. 

Extraction  of  the  Worm.  —  After  securing  the  worm, 
attempts  should  be  made  to  extract  it  every  twenty-four 
hours.  As  much  as  6  or  8  inches  a  day  may  be  extracted 
and  wound  upon  the  quill,  which  should  then  be  fastened 
parallel  to  the  limb  with  two  pieces  of  strapping,  and  the 
part  dressed  with  lint  soaked  in  a  solution  of  alum,  8  grs.  to 
the  ounce.  This  prevents  the  part  becoming  dry,  and  also 
strengthens  the  worm,  and  so  tends  to  diminish  the  danger  of 
its  breaking.  The  natives  are  very  skilful  in  extracting  the 
worm  by  making  an  incision  over  it  and  rapidly  turning  it 
out,  but  this  requires  great  skill. 

Constitutional  symptoms,  when  they  arise,  must  be  treated 
on  general  principles,  and  if  malaria  complicates  matters, 
the  use  of  quinine  must  be  energetically  pushed. 

Egyptian  Chlorosis. 

This  disease  is  common  in  Egypt.  It  is  caused  by  the 
ingestion  of  the  Anchylostomum  duodenale,  from  which  it  is 
reported  that  a  fourth  part  of  the  population  suffers.  It  is 
said  to  be  a  stage  in  the  development  of  the  Dochmius  trigono- 
cephalus  of  the  dog.  It  attaches  itself  to  the  lower  portion  of 
the  human  duodenum  and  to  the  jejunum.  The  symptoms 
caused  by  the  presence  of  this  worm  are  those  of  pernicious 
anaiuiia.  For  debilitated  individuals  it  may  prove  fatal  in  a 
few  weeks.  In  well-fed  persons  the  disease  may  exist  for  two 
or  three  years.  It  is  found  that  the  best  treatment  to  get  rid 
of  the  worms  is  the  administration  of  the  milky  juice  of  the 


60  On  the  Geographical  Distribution  of 

Ficus  doliaria  or  of  the  Carica  dodekaphylla,  or  Thymol  is 
often  of  great  use.  Dr  Sandwith  gives  to  adults  2  grms.  at 
8  A.M.  with  25  grms.  of  brandy,  and  repeats  the  dose  at 
10  A.M.  At  noon  a  dose  of  castor-oil  should  be  given.  Care 
should  be  taken  in  very  debilitated  subjects.  If  necessary,  this 
treatment  may  be  repeated  in  a  week.  It  is  well  to  remem- 
ber that  the  patient  should  keep  perfectly  still  after  taking 
the  medicine,  as  giddiness  and  faintness  are  apt  to  ensue. 
The  brandy  is  given  both  to  dissolve  the  drug  and  also  to 
prevent  collapse.  The  subsequent  treatment  of  the  anicmia 
which  has  been  produced  must  be  carried  out  upon  general 
principles.  It  will  be  found  that  Levico  water  is  very  useful 
in  improving  the  condition  of  the  blood,  but  as  it  would  not 
be  easily  carried,  iron  and  arsenic  should  be  given  thrice 
daily. 

Snake-Bites. 

One  or  two  hints  with  regard  to  the  prevention  of  snake- 
bites may  not  be  out  of  place.  In  order  to  prevent  snakes 
from  entering  a  house,  it  is  advisable  to  have  a  path  four  or 
five  feet  wide  encircling  it,  and  covered  with  rough  stones. 
Keep  the  verandahs  free  from  frogs,  especially  during  the 
wet  season.  A  frog  is  a  temptation  which  a  snake  has  little 
or  no  power  to  resist  (Waring).  Place  a  coil  of  camel' s-hair 
rope  round  the  bed  ;  snakes  will  not  cross  it.  Never  get  out 
of  bed  during  the  night  with  bare  feet  without  a  light  and 
first  seeing  if  the  way  is  clear.  If  a  snake  is  seen  coiled  up 
or  in  an  apparently  lifeless  state  in  the  road,  it  should  be 
avoided,  as  it  is  probably  only  torpid  with  cold,  not  dead  (Dr 
Chevers).  It  is  well  to  remember  that  a  poisonous  snake- 
bite may  be  diagnosed  by  the  two  well-marked  wounds  made 
by  the  fangs.  In  treating  snake-bites,  it  is  probable  that  the 
hypodermic  injection  of  strychnine,  as  recommended  by  Dr 
A.  Miiller,  is  the  best  treatment  we  possess.  "  Nothing  less 
than  16  ms.  of  the  liquor,  strychnite  (B.T.),  in  very  urgent 
cases  even  20  or  25  ms.,  should  be  injected  into  any  person 
over  fifteen  years  of  age.  Even  children  may  require  these 
large  doses,  as  they  are  determined  by  the  quantity  of  the 
poison  they  have  to  counteract,  and  are  kept  in  check  by  it. 


Tropical  Diseases  in  Africa.  61 

The  action  of  tlie  antidote  is  so  prompt  and  decisive  that  not 
more  than  fifteen  or  twenty  minutes  need  elapse  after  the 
first  injection  before  further  measures  can  be  decided  on.  If 
tlie  poisoning  symptoms  sliow  no  abatement  by  that  time, 
a  second  injection  of  the  same  strengtli  should  be  made 
promptly,  and,  unless  it  is  followed  by  a  decided  improve- 
ment, a  third  one  again  after  the  same  interval.  As  the 
action  of  strychnine,  when  applied  as  an  antidote,  is  not 
cumulative,  no  fear  need  be  entertained  of  violent  effects 
suddenly  breaking  out  after  these  large  doses  repeated  at 
short  intervals." 


Yaics  or  Framhoesia. 

This  disease  consists  of  an  eruption  of  yellow  or  reddish- 
yellow  tubercles,  which  gradually  develop  into  a  moist 
exuding  fungus,  without  constitutional  symptoms,  or  with 
such  only  as  result  from  ulceration  and  prolonged  discharge, 
namely,  debility  and  prostration.  Its  predisposing  causes 
are  filth,  vitiated  atmosphere,  and  want  of  animal  food  in  a 
tropical  climate.  It  is  more  common  among  the  coloured 
than  the  white  population.  It  is  epidemic  and  contagious  by 
actual  contact.  The  period  of  incubation  ranges  from  three 
to  ten  weeks.  It  is  not  liable  to  recur.  Its  duration  is  from 
two  to  four  months,  but  it  may  last  for  a  year.  It  frequently 
runs  in  famiKes,  and  is  apt  to  be  communicated  by  clothing, 
especially  by  boots.  Children  are  most  subject  to  it,  then  men, 
lastly  women.  The  disease  often  begins  with  a  severe  febrile 
attack ;  in  a  few  days  small  spots  appear,  principally  on  the 
face,  in  the  axilla,  in  the  neighbourhood  of  the  groin,  or  on 
the  feet.  They  increase  gradually  until  they  are  as  large  as 
a  pin's  head,  the  surrounding  skin  acquiring  an  unhealthy 
aspect.  In  about  a  week  these  little  tubercular  swellings 
exude  a  thin  sanious  fluid,  forming  dry  scales  or  scabs.  The 
surface  remains  covered  with  these  scabs  for  a  week  or  ten 
days,  if  undisturbed,  during  which  time  a  fungoid  excrescence 
grows  underneath  it,  so  as  to  form  a  projecting  mass  one  or 
two  inches  in  diameter.  The  skin  around  is  hard  and  firm. 
Crops  of  yaws  arise  at  different  periods.     After  maturity 


G2  On  the  Geo(jraphical  Distribution  of 

they  may  remain  stationary  for  some  weeks.  One  excrescence 
in  each  group  is  generally  larger  than  the  rest,  and  is  called 
the  "  mother "  or  head  yaw.  The  disease  runs  a  definite 
course,  exactly  like  the  exanthematous  eruptions.  "When 
the  ulcerations  heal  they  leave  a  pigmented  stain,  but  the 
"  mother  "  yaw  leaves  a  large  scar. 

Treatment. — The  preventive  treatment  is  cleanliness,  good 
diet,  and  the  avoidance  of  contact  with  persons  suffering 
from  the  disease  or  with  their  clothing. 

The  general  treatment  must  be  guided  by  the  symptoms 
present,  as  the  disease  cannot  be  abbreviated.  Full  animal 
diet  should  be  given,  and  perfect  cleanliness  enjoined,  with 
exercise  and  plenty  of  fresh  air.  Tonics  and  alteratives  are 
required  from  the  first ;  arsenic  is  extremely  useful,  so  are  the 
mineral  acids,  sarsaparilla,  and  bark.  Iodide  of  potassium 
also  is  given,  in  combination  with  liquor  arsenicalis  and 
alkalis,  and  is  exceedingly  useful  when  the  ulcers  are 
indisposed  to  heal. 

With  regard  to  local  applications,  carbolic  acid  solutions,  or 
dilute  nitrate  of  mercury  ointment,  or  creosote  in  the  strength 
of  1  dr.  to  1  oz.  of  lanoline,  should  be  employed.  Authorities 
differ  as  to  the  administration  of  mercury  in  this  disease ;  it 
should  at  any  rate  be  avoided  in  debilitated  subjects. 

Elephantiasis  Arabum. 

This  is  a  chronic  disease,  which  may  be  said  to  be 
characterised  by  an  enormous  hypertrophy  of  the  skin  and 
subcutaneous  tissue,  caused  by  recurrent  inllammation  of  the 
vessels  and  lymphatics  in  the  part  affected.  It  is  unnecessary 
to  refer  at  any  great  length  to  this  disease,  because  it  is  very 
rarely  that  white  residents  in  Africa  are  affected  by  it. 
Various  parts  of  the  body  are  attacked — the  legs,  scrotum, 
pudendum,  abdomen,  and  breasts ;  most  chietly,  however,  it 
is  found  allecting  either  the  legs  or  the  scrotum.  Males  are 
most  frequently  attacked  at  about  the  age  of  puberty.  It  is 
non-contagious ;  it  is  not  hereditary ;  its  cause  is  unknown. 

The  treatment,  when  the  disease  has  once  become  manifest, 
is  removal  from  the  area  in  which  it  was  contracted.     It  was 


Tropical  Diseases  in  Africa.  G3 

once  supposed  that  tying  the  femoral  artery  would  cure  the 
growth  in  the  leg,  but  that  treatment  is  unsatisfactory.  Per- 
sistent strapping  from  the  foot  upwards  has  also  been  recom- 
mended, but  it  likewise  does  little  good.  The  scrotum  may 
be  removed,  and  even  enormous  tumours  weighing  40  to  60 
lbs.  are  often  successfully  treated  in  this  manner.  In 
a  case  I  treated  lately,  in  which  the  disease  was  limited  to 
the  body  and  the  thighs  as  far  as  the  knees,  I  obtained  a 
cure,  by  enjoining  absolute  rest,  giving  the  patient  a  hot 
bath  every  day,  a  moderate  amount  of  food,  chiefly  milk, 
having  the  patient  regularly  massaged,  and  by  applying  the 
constant  current  for  twenty  minutes  each  day.  A  mixture 
was  prescribed  containing  quinine,  arsenic,  iron,  and 
strychnine,  and  the  bowels  were  regulated  by  the  frequent 
administration  of  aperients. 

Leprosy, 

This  is  a  disease  caused  by  a  bacillus  which  is  chiefly  found 
in  the  exudation  cells,  but  also  in  the  diseased  connective 
tissue,  more  rarely  in  the  blood-vessels.  There  are  three 
varieties — tuberculated,  non-tuberculated,  and  anaesthetic. 
The  recent  Commission  which  has  been  held  on  the  subject 
does  not  believe  that  the  disease  is  either  contagious  or 
hereditary.  It  is  practically  incurable,  but  benefit  may  be 
obtained  by  the  internal  and  external  administration  of 
chaulmoogra  oil,  and  quite  recently  extract  of  the  thyroid 
o-land  has  been  given  with  marked  success.  It  has  been 
stated  that  the  production  of  leprosy  is  due  to  extremes, 
frequent  and  rapid  transitions  of  temperature,  but  it  is  not 
so.  Various  articles  of  diet  have  been  blamed  for  its  cause 
— fish  diet,  salt  or  rotten  fish,  immoderate  use  of  pork,  and 
the  use  of  decomposing  rice  or  maize,  but  none  of  these 
articles  of  diet  can  be  its  exciting  cause. 

In  Central  Africa  the  natives  certainly  believe  that  the 
disease  is  contagious,  and  they  also  believe  that  sleeping  in 
a  hut  which  has  been  inhabited  by  a  leprous  patient  is 
dangerous.  It  is,  indeed,  necessary  to  avoid  contact  with 
lepers  as  much  as  possible.  White  men  in  Africa  rarely,  if 
ever,  suffer  from  this  disease. 


C-i  On  the  Oeographical  Distribution  of 

Yclloxo  Fever. 

Yellow  fever  is  a  pestilential  contagious  disorder  of  a 
continuous  and  special  type,  depending  for  its  origin  and 
spread  on  a  temperature  not  lower  tlian  70°  F.  As  a  general 
rule  it  occurs  but  once  in  a  lifetime.  Its  spread  is  favoured 
by  the  gathering  together  of  persons  born  in  a  cold  climate. 

Etiology. — Yellow  fever  is  entirely  distinct  from  malaria. 
Its  production  requires  a  temperature  of  from  GS""  to  70°  Y. 
When  once  originated,  however,  an  epidemic  may  spread  at 
a  lower  temperature,  but  it  dies  out  if  the  temperature  falls 
to  freezing  point.  The  influence  of  moisture  in  the  air 
constitutes  a  second  factor  in  the  production  of  yellow  fever. 
Abundant  continuous  rain  does  not  infrequently  bring  an 
epidemic  to  an  end,  probably  by  modifying  the  temperature, 
but  a  certain  saturation  of  the  atmosphere  is  an  essential 
condition  for  the  production  of  the  disease — probably  74  per 
cent,  of  moisture.  Epidemics  cease  when  the  amount  of 
moisture  is  as  low  as  58  per  cent.  The  only  inlluence  which 
•wind  has  on  yellow  fever  is  by  its  modifying  the  temperature. 
The  disease  rarely  leaves  the  sea  coasts  and  the  shores  of 
large  rivers ;  it  arises  in  the  filthy  quarters  of  towns,  in  the 
centres  of  poverty  where  the  people  are  densely  crowded. 
The  geological  characters  of  the  soil  have  apparently  no 
connection  with  the  production  of  the  disease.  It  is  most 
interesting  to  notice  the  influence  which  circumstances  of 
race,  nationality,  and  acclimatisation  exert  upon  the  disease. 
Where  it  is  endemic  or  epidemic,  newly-arrived  strangers,  or 
such  persons  as  have  not  yet  become  fully  acclimatised,  are 
the  persons  who  suffer  most.  This  is  well  seen  if  a  large 
body  of  troops  or  a  shipload  of  emigrants  arrive  at  any  place 
where  tlie  disease  already  exists,  though  it  may  be  very 
mildly.  An  epidemic  at  once  springs  up,  and  the  new 
arrivals  are  the  first  persons  attacked.  The  degree  to  which 
this  proclivity  of  strangers  exists  will  depend  to  a  great 
extent  on  their  nationality,  that  is,  on  the  mean  annual 
temperature  of  their  native  country.  The  liability  to  attack, 
as  well  as  the  mortality  amongst  the  newcomers,  bears  a 
close  relation  to  the  distance  from  the  equator  of  their  place 


Tropical  Diseases  in  Africa.  G5 

of  birth.  Although  no  absolute  immunity  is  acquired  by 
acclimatisation,  yet  it  is  true  that  a  certain  amount  of 
immunity  is  possessed  by  those  who  have  lived  for  a  con- 
siderable period  in  any  locality  constantly  or  frequently 
visited  by  the  disease.  The  chances  of  immunity  appear  to 
be  always  in  direct  proportion  to  the  length  of  residence 
at  the  headquarters  of  the  disease,  but  no  protection  is 
acquired  except  by  those  who  have  passed  through  a 
previous  epidemic  period  without  quitting  the  country. 
Any  benefit,  however,  gained  by  acclimatisation  is  imme- 
diately lost  on  change  of  residence,  even  though  that  change 
be  to  a  healthier  locality.  This  remark  applies  equally  to 
negroes  and  white  men,  but  negroes  suffer  far  less  from 
yellow  fever  than  do  the  whites. 

The  nature  of  the  yellow-fever  poison  has  been  found  by 
Dr  Domingos  Freire  to  be  a  specific  cryptococcus.  He  has 
also  found  out  that  this  micro-organism  secretes  an  alkaloid 
resembling  a  ptomaine,  which  acts  as  a  violent  poison.  With 
regard  to  contagion,  there  is  no  doubt  that  it  may  be  con- 
veyed by  fomites  or  merchandise,  as  also  by  ships,  and  it 
can  be  transported  farther  by  sea  than  on  land.  Hence  the 
necessity  during  an  epidemic  of  completely  isolating  vessels 
in  a  harbour.  It  does  not  appear  that  contact  with  the  sick 
has  power  to  spread  the  disease.  Electricity  appears  to 
have  a  singular  and  baneful  influence  npon  persons  suffering 
from  yellow  fever. 

It  is  impossible  in  the  space  at  my  disposal  to  detail  the 
symptoms  of  yellow  fever,  but  there  are  a  few  well-marked 
symptoms  which  deserve  notice.  First,  the  attack  is  sudden, 
there  is  a  want  of  correlation  between  the  pulse  and  tem- 
perature, albuminuria  is  invariably  present,  the  patient 
suffers  from  the  black  vomit,  from  a  general  hajmorrhagic 
tendency,  and  from  a  yellow  discoloration  of  the  skin,  olten, 
too,  from  suppression  of  urine. 

Prophijladic  Treatment. — Avoid  the  yellow-fever  season  if 
possible,  namely,  the  hot  and  rainy  season ;  avoid  chills  by 
wearing  proper  clothing ;  avoid  exposure  to  the  sun  as  much 
as  possible.  Individuals  attacked  by  the  disease  should  be 
isolated.      Eesidences   should  be    chosen    at    the    highest 

E 


66  On  the  Geographical  Distribution  of 

altitudes  possible,  in  any  case  the  second  storey  is  preferable 
to  the  first,  and  in  camp  the  ground  should  be  disturbed  as 
little  as  possible.  Strictest  disinfection  should  be  employed. 
The  water  and  food  supply  should  be  well  cared  for,  and  it 
should  be  remembered  that  the  yellow-fever  bacillus  has 
been  found  in  the  soil.  Exposure  during  the  night  is 
inadvisable,  for  Carlos  Finlay  has  demonstrated  that  the 
disease  can  be  communicated  by  the  mosquito.  Yellow 
fever  is  also  a  disease  in  which  quarantine  is  necessary  and 
effectual ;  not  only  is  it  necessary  to  place  persons  coming 
from  an  infected  place  under  observation,  but  their  clothing 
and  goods  should  be  thoroughly  disinfected. 

Inoculation. — Since  the  researches  of  Freire  and  Finlay,  it 
is  possible  to  employ  protective  inoculation  against  yellow 
fever.  Finlay  allows  a  mosquito  to  bite  a  yellow-fever 
patient  and  then  a  healthy  person ;  a  mild  attack  of  yellow 
fever  is  induced,  protecting  the  person  thus  treated  from  a 
subsequent  attack.  Dr  Freire,  having  isolated  the  yellow 
fever  micro-organism  by  a  series  of  cultivations,  attenuates  it 
and  produces  a  fluid  which  almost  entirely  protects  persons 
from  yellow  fever.  In  no  case  has  the  inoculation  been 
harmful,  and  the  mortality  of  those  inoculated  was  only 
rather  more  than  04  per  cent,  in  10,881  cases  inoculated 
(1890),  showing  that  this  procedure  confers  almost  certain 
immunity  from  the  disease. 

Treatment. — With  regard  to  the  treatment  of  yellow  fever, 
little  can  be  said.  It  is  important  tliat  each  patient  should 
be  allowed  at  least  2000  cubic  feet  of  space  ;  the  room 
should  be  kept  at  an  equable  temperature,  and  the  patient 
protected  from  draughts ;  indeed,  many  advise  the  treating 
the  patients  in  tents  or  in  the  open  air.  Absolute  rest  in  a 
recumbent  position  must  be  rigidly  maintained.  The  patients 
must  be  lightly  but  warmly  clothed,  heavy  blankets  being 
avoided.  Doctors  and  nurses  should  be  cheerful,  and  en- 
courage the  patients  as  much  as  possible. 

With  regard  to  drugs,  no  specific  for  yellow  fever  is  known, 
and,  practically,  symptoms  must  be  treated.  I  should  be 
inclined  myself  to  recommend  either  of  the  two  following 
treatments.     The  first  is  recommended  by  Nelson.     He  gives 


Tropical  Diseases  in  Africa.  67 

15  grs.  of  quinine,  half  an  ounce  of  sulphate  of  sodium,  dilute 
sulphuric  acid,  and  tincture  of  cardamoms,  at  first.  If  after 
the  first  two  days  the  temperature  remains  above  100°  F., 
with  the  usual  symptoms  of  yellow  fever,  he  adds  phosphoric 
acid  largely  diluted  with  water,  every  hour  or  two.  Dia- 
phoresis is  induced  by  vapour  baths ;  the  diet  consists  of  iced 
milk  and  beef  broth  in  small  quantities  at  frequent  intervals. 
On  the  other  hand,  Sternberg  recommends  bicarbonate  of 
soda  150  grs.,  bichloride  of  mercury  |rd  gr.,  water  2  pints; 
an  ounce  and  three-quarters  to  be  given  ice-cold  every  hour. 
This  treatment  is  slightly  modified  by  Mitchell,  who  increased 
the  dose  of  the  bicarbonate  of  soda  to  4  drs.,  and  the  bi- 
chloride to  half  a  grain.  When  patients  are  thus  treated 
from  the  first  day,  vomiting  rarely  occurs.  Diuresis  is  well 
maintained.  After  the  eighth  or  tenth  day  it  is  necessary  to 
suspend  the  bicarbonate  of  soda  and  give  stimulants,  and  to 
combat  the  adynamia  and  the  haemorrhages,  etc.,  with  the 
customary  measures.  For  the  vomiting  I  believe  turpentine 
is  the  best  remedy;  it  may  be  administered  either  by  the 
mouth  or  by  eneraata,  and  the  body  may  be  rubbed  with  a 
mixture  of  turpentine  and  olive  oil.  If  suppression  of 
urine  occurs,  I  know  of  no  better  treatment  than  to 
apply  a  digitalis  leaf  poultice  to  the  loins,  and  to  inject 
into  the  rectum  a  pint  or  more  of  ice-cold  water  at  regular 
intervals. 

The  discharges  of  the  patient  are  best  disinfected  with 
either  chloride  of  lime  or  perchloride  of  mercury.  Bedding 
and  clothing  are  better  destroyed  by  fire.  Hospital  wards  or 
the  holds  of  a  ship  should  be  fumigated  with  nitrous  acid  for 
at  least  forty-eight  hours,  and  then  all  the  woodwork  washed 
with  chloride  of  lime.  For  disinfecting  the  bilge-water  of 
ships,  chloride  of  lime  must  be  employed,  or,  better  still,  the 
bilge-water  should  be  pumped  out. 

Typhoid  Fever. 

I  have  only  a  few  remarks  to  make  on  this  subject. 
Typhoid  fever  certainly  exists  in  Africa,  and  it  is  also  certain 
that  the  death-rate  is  higher  there  than  it  is  in  more  tem- 
perate zones.     I  hold  the  view  that  the  disease  is  due  to 


08  On  the  Geographical  Distribution  of 

Eberth's  bacillus,  and  I  have  ouly  a  few  words  to  say  with 
regard  to  the  prevention  of  the  disease. 

Typhoid  fever  is  most  prevalent  during  the  hottest  months 
in  Africa,  and  it  should  be  remembered  that  sandy  soil 
favours  its  spread,  as  the  dried  excreta  of  patients  may  be 
conveyed  by  the  wind  unless  care  be  taken.  The  utmost 
care  should  be  taken  to  ensure  the  fullest  sanitary  pre- 
cautions. The  excreta  must  be  properly  disinfected,  and  the 
water-supply  should  not  only  be  carefully  selected,  but  all 
water  should  be  filtered  and  boiled.  Milk,  too,  deserves 
special  attention.  The  meat-supply  should  also  be  investi- 
gated, and  all  tainted  supplies  rigorously  rejected.  It  is 
necessary  also  to  pay  attention  to  the  vegetables,  as  un- 
doubtedly they  may  carry  the  infection.  All  patients  should 
be  thoroughly  isolated,  and  their  bedding  and  linen  destroyed. 
It  is  very  necessary,  in  my  opinion,  to  get  rid  of  the  idea  that 
typho-malarial  fever  exists,  and  in  cases  of  doubt  a  bacterio- 
logical investigation  should  be  made,  which  failing,  the 
disease  should  be  treated  by  quinine,  and  if  it  does  not 
succeed  in  reducing  the  temperature,  then  the  case  should  be 
treated  as  one  of  typhoid  fever.  The  cases  which  have  been 
designated  typho-malarial  fever  are  in  reality  severe  cases  of 
remittent  fever  lapsing  into  a  typhoid  state,  or  else  enteric 
fever  modified  by  its  occurrence  in  a  patient  who  has  previ- 
ously suffered  much  from  malaria,  or  occurring  simultaneously 
with  an  attack  of  malarial  fever  (Duncan). 

Tropical  Dysentery  and  Diarrluxa. 

Dysentery  has  practically  the  same  distribution  as  malaria 
in  Africa,  and  there  are  ouly  some  minor  differences  met 
with  in  the  distribution  of  the  two  diseases.  It  does  not 
always  follow  that  the  maximum  intensity  of  the  diseases 
coincides. 

In  referring  to  the  etiology  and  prevention  of  dysentery,  I 
may,  to  economise  space,  include  diarrhoea  as  well,  for, 
although  I  believe  true  tropical  dysentery  to  be  due  to  the 
amoeba  discovered  by  Cartulis  of  Alexandria,  which  dis- 
covery  has   been    coulirmed   by  American    observers    (see 


Tropical  Diseases  in  Africa.  69 

Johns-Hopkins  Hospital  Eeports),  yet  both  diseases  may  to 
a  certain  extent  be  combined,  and  the  precautions  necessary 
to  avoid  the  one  are  those  which  would  prevent  the  other. 

Both  diseases  are  most  prevalent  in  the  hot  and  rainy 
seasons;  both  are  liable  to  be  produced  by  rapid  alternations 
of  temperature  and  by  chill.  Therefore  persons  in  Tropical 
Africa  should  avoid  chill  by  means  of  careful  clothing,  and 
by  the  invariable  use  of  a  cholera  belt.  Excessive  exertion 
also  predisposes  to  both  diseases,  and  both  are  especially  met 
with  in  damp,  swampy  places,  and  in  all  districts  where  the 
soil  is  impregnated  with  decaying  vegetable  debris.  The 
drinking  water  should  be  as  pure  as  possible,  and  in  cases 
where  the  water-supply  is  doubtful,  it  should  be  filtered 
and  boiled.  All  stagnant  water  should  be,  if  possible, 
avoided.  It  is  also  of  importance  to  remember  that  both  a 
monotonous  diet  and  salt  rations  frequently  induce  diarrhosa, 
and  predispose  to  dysentery.  Unripe  fruit,  and  especially 
over-ripe  fruit,  should  be  avoided.  There  is  no  doubt  that  in 
Africa  many  cases  of  diarrhoea  and  dysentery  are  induced  by 
exposure  to  the  night  air,  and  also  by  sleeping  on  the  ground. 
Where  they  are  prevalent,  it  is  well  to  isolate  the  patients, 
and  to  carefully  disinfect  their  excreta ;  and  finally,  it  must 
be  borne  in  mind  that  malaria  may  complicate  both  diseases, 
and  that  then,  unless  the  malarial  factor  is  taken  into  account, 
the  disease  cannot  be  cured. 

One  may  summarise  the  predisposing  causes  of  dysentery 
and  diarrhoea  as  follows: — Frequent  exposure  to  malaria, 
great  bodily  fatigue  or  excessive  anxiety  and  mental  distress, 
excess  in  the  use  of  alcohol  and  tobacco  and  narcotics,  over- 
crowding, the  use  of  tainted  food  or  the  prolonged  employment 
of  salt  provisions,  and  lastly,  the  too  frequent  employment  of 
strong  purgative  medicines.  The  exciting  causes  of  these 
diseases  are — unwholesome  drinking  water,  the  use  of 
indifferent  food,  great  and  sudden  vicissitudes  of  temperature 
and  chill,  impure  air,  intestinal  worms,  and  abscess  of  the 
liver. 

Nothing  need  be  said  as  to  the  treatment  of  diarrhoea,  as 
this  must  be  carried  out  on  general  principles;  but  with 
regard  to  dysentery,  my  experience  points  to  the  advisability 


70  On  the  Geographical  Distribution  of 

of  treating  it  in  Africa  with  large  doses  of  ipecacuanha. 
This  I  consider  the  only  treatment  of  any  practical  value. 
After  sending  the  patient  to  bed,  a  mustard  poultice  should 
be  applied  to  the  epigastrium,  and  30  drops  of  laudanum 
given  at  once.  After  half  an  hour  30  or  40  grs.  of  powdered 
ipecacuanha  should  be  given,  in  as  small  a  quantity  of  fluid 
as  possible.  A  similar  dose  may  be  repeated  in  twelve  or 
twenty-four  hours  if  necessary;  after  this,  during  the  suc- 
ceeding days,  the  dose  should  be  gradually  lessened  to  10  or 
15  grs.  a  day,  until  the  patient  has  perfectly  recovered.  In 
very  severe  attacks,  as  much  as  2  drs.  of  the  powder  have 
been  given  without  producing  vomiting.  Fairly  large  doses 
of  quinine  are  required  in  all  cases  of  malarial  dysentery. 
In  the  treatment  of  the  scorbutic  form  of  dysentery,  lime 
juice,  fruit,  and  vegetables  should  be  given,  with  as  much 
animal  food  as  the  stomach  will  bear.  In  treating  natives 
in  Africa,  the  great  difficulty  is  to  ensure  proper  diet,  for, 
unless  the  patient  is  carefully  watched  during  convalescence, 
a  relapse  will  follow  the  least  indiscretion.  A  sea  voyage  is 
beneficial  when  a  patient  is  convalescent,  but  it  is  not  to  be 
recommended  during  the  continuance  of  the  attack. 

Malaria. 

There  are  few  regions  in  Africa  where  malaria  is  not  a 
scourge,  and  those  few  have  been  indicated  in  my  survey  of 
the  various  African  regions. 

I  may  say  at  the  outset  that  I  believe  malaria  to  be 
produced  by  the  ha^matozoon  discovered  by  Laveran.  His 
researches  have  been  confirmed  by  observers  in  Europe,  India, 
America,  and  Africa.  The  life-history  of  the  hamatozoon  we 
do  not  know,  and  therefore  we  can  only  state  that  it  requires  a 
mean  summer  isobar  of  58°-60°  F.,  and  considerable  moisture; 
also,  other  things  being  equal,  the  greater  amount  of  organic 
matter  in  the  soil,  the  more  virulent  will  the  production  of 
the  disease  be. 

Of  the  various  types  of  malarial  fever,  the  intermittent 
is  the  most  widely  distributed,  the  remittent  and  pernicious 
fevers  ouly  being  met  with  in  comparatively  limited  areas, 


Tropical  Diseases  in  Africa.  71 

and  in  Africa  these  are  found  upon  the  coasts,  along  the 
rivers,  and  in  the  water-logged  swampy  districts  at  an  alti- 
tude of  under  3000  feet.  The  quotidian  and  tertian  types  of 
intermittent  fever  are  the  ones  most  frequently  met  with. 
The  type  of  fever  stands  in  a  definite  relation  to  the  intensity 
of  the  malarial  process ;  thus  we  find  that  the  tertian  type 
prevails  in  those  regions  of  Tropical  Africa  where  the  malarial 
process,  although  indigenous,  is  more  sparingly  produced. 
The  frequency  of  the  occurrence  of  the  quotidian  type  of 
fever,  either  in  endemic  areas  or  in  epidemics,  is  in  direct 
proportion  to  the  severity  of  the  process.  When  an  epidemic 
wave  of  malarial  fever  passes  over  a  district,  the  tertian  type 
is  seen  at  its  outbreak,  whereas  at  the  height  of  an  epidemic, 
or  whenever  it  assumes  a  severe  character,  the  quotidian 
type  obtains;  and  as  the  outbreak  of  sickness  abates,  one 
meets  with  a  return  to  the  types  of  fever  having  a  longer 
interval  between  the  paroxysms.  In  the  higher  latitudes  in 
Africa,  and  also  in  the  higher  altitudes,  the  quartan  type  of 
fever  makes  its  appearance. 

All  races  suffer  from  malaria,  although  the  Negroes  suffer 
less  from  it,  always  provided  that  they  do  not  migrate.  In 
Africa,  as  in  all  parts  of  the  world,  strangers  sufler  more 
severely  from  it  than  does  the  indigenous  population.  The 
incidence  of  malaria  is,  to  a  certain  extent,  governed  by  the 
seasons.  In  those  places  where  it  is  endemic,  it  occurs  all 
the  year  round,  but  where  it  is  only  slightly  developed  there 
are  two  maxima,  one  in  spring  and  one  in  autumn,  and  a 
considerable  decrease  in  the  disease  in  the  interval.  In 
Africa,  in  the  worst  malarious  regions,  the  disease  is  practic- 
ally most  rife  at  the  beginning  and  at  the  end  of  the  rains. 
The  relation  which  malaria  bears  to  heat  is  as  follows :  the 
greater  the  mean  summer  temperature  (moisture,  etc.,  of 
course  being  taken  into  account)  the  more  malaria,  the 
amount  of  malaria  decreasing  with  the  mean  annual  tempera- 
ture of  the  place. 

The  influence  of  rain  or  moisture  has  undoubtedly  much 
to  do  with  the  production  and  spread  of  malaria.  With 
reference  to  the  rains,  the  malarial  poison  is  most  virulent 
either  when  they  set  in  after  a  long  period  of  heat,  or  when 


72  On  the  Geographical  Distribution  of 

tlie  rains  cease  and  give  place  to  warm  dry  weatlier.  An 
endemic  outbreak  of  malaria  and  its  epidemic  spread  are 
both  notably  diminished  at  the  height  of  the  rains,  if  they 
are  very  abundant,  but  the  malarial  process  is  developed 
more  abundantly  in  wet  than  in  dry  years.  These  remarks 
are  well  ilhistrated  by  the  behaviour  of  malaria  in  different 
districts.  In  Equatorial  Central  Africa,  where  the  rainfall  is 
fairly  equally  distributed  throughout  the  year,  the  amount  of 
the  disease  remains  practically  the  same,  but  in  regions,  e.g., 
along  the  White  Xile  to  the  north  of  Lado,  where  there  are 
two  wet  seasons,  a  rise  and  fall  in  the  production  of  malaria 
is  manifest.  But  it  is  not  alone  rainfall  which  influences  the 
production  of  the  disease.  Drainage  from  rivers,  lakes,  and 
pools,  periodical  or  irregular  inundations,  and  the  height  of 
the  sub-soil  water,  influence  its  production.  This  last  point 
is  of  importance,  because  it  explains  the  occurrence  of  malaria 
in  localities  remote  from  river  basins,  in  the  Sahara,  in 
Darfur,  etc. 

Although  the  geological  characters  of  the  country  would 
appear  to  exert  little  or  no  influence  on  the  production  of 
the  disease,  it  is  the  contrary  with  the  physical  characteristics 
of  the  soil.  Clay,  loam,  clayey  marl,  and  marshy  soil  are 
most  favourable  to  the  production  of  the  disease.  A  porous 
chalky  soil  is  less  favourable,  and  a  sandy  soil  least  so, 
provided  that  they  do  not  rest  either  upon  clay  or  firm  rock. 
Again,  the  greatest  amount  of  malaria  will  be  found  where 
the  organic  matter  in  the  soil  is  greatest.  It  is  also  an 
undoubted  fact  that  changes  in  the  soil,  produced  by  cultiva- 
tion or  its  neglect,  influence  the  production  of  the  disease. 
In  well-cultivated  countries  malaria  disappears,  and  if  marshy 
districts  are  well  drained  or  completely  covered  with  water, 
the  disease  is  also  diminished. 

The  configuration  of  the  ground  also  causes  a  local  effect, 
for  it  is  found  that  the  disease  is  more  virulent  in  the  lowest 
altitudes  ;  even  the  difference  of  50  or  100  feet  in  altitude 
in  a  plain  makes  a  considerable  difference  as  to  the  sahibrity 
or  otherwise  of  a  given  spot. 

Winds  act  only  indirectly  on  malaria,  as,  for  instance,  by 
moderating  temperature ;  they  may,  however,  act  directly  in 


Tropical  Diseases  in  Africa.  73 

the  diffusion  of  the  poison  or  in  preventing  it  exercising  its 
potent  effects.  Wind  may  carry  the  malarial  poison  from  a 
marsh  to  a  distance  of  some  two  or  three  miles.  Malaria 
may  rise  to  a  height  of  600  or  700  feet  in  a  calm  atmosphere  ; 
wind  will  prevent  this  vertical  diffusion. 

Water  can  convey  the  malarial  poison,  but  it  is  unknown 
at  present  how  far  it  can  carry  it. 

The  poison  is  ponderable,  and  affected  by  barometrical 
pressure,  and  it  is  possible  also  that  food  may  be  con- 
taminated by  it. 

The  influence  of  jungle  and  forest  on  malaria  must  also 
be  noticed,  because  so  much  of  Central  Africa  is  covered  by 
one  or  other.  In  a  jungle,  malaria  is  intensely  virulent,  and, 
owing  to  want  of  ventilation  by  the  penetration  of  winds, 
it  is  there  in  a  very  concentrated  form.  In  forests  the 
production  of  malaria  is  to  some  extent  lessened  by  the 
shade,  and  by  the  trees  diminishing  the  amount  of  rainfall 
reaching  the  soil.  There  is  no  doubt  that  forests  often  act 
as  a  screen  or  filter,  and  therefore  protect  the  district  from 
malaria  when  they  lie  between  it  and  a  marsh. 

With  regard  to  the  prevention  of  malaria,  much  may  be 
done  by  careful  drainage,  not  only  of  the  surface,  but  of  the 
sub-soil  water.  Great  care  should  be  exercised  in  the  choice 
of  a  residence,  ravines  being  avoided,  also  the  neighbourhood 
of  swamps.  Settlements,  and  even  individual  houses,  should 
be  on  the  most  elevated  situations,  and  it  should  be  remem- 
bered that  malaria  is  less  rife  in  the  centre  of  towns, 
especially  if  the  streets  are  narrow  and  crooked.  The 
proposal  to  build  houses  in  the  form  of  a  hollow  square 
is  to  be  commended,  and  in  all  cases  they  should  be 
constructed  with  a  blank  wall  to  the  prevailing  wind, 
especially  if  that  wind  blows  over  a  marsh.  The  thick 
jungle  in  the  neighbourhood  of  a  settlement  should  be 
destroyed,  but  care  should  be  taken  not  to  remove  either 
thickets  or  trees  between  a  settlement  and  a  marsh.  The 
oround  under  and  around  a  habitation  should  be  rendered 
impervious  to  water  and  air,  and  the  sleeping  rooms  should 
be  in  the  second  storey.  In  camping  out  even,  considerable 
protection  may  be  obtained  by  sleeping  in  a  mosquito  curtain 


74  On  the  Geographical  Distribution  of 

in  a  hammock  slung  between  two  trees  ;  this  is  far  preferable 
to  sleeping  on  the  ground.  A  good  deal  may  be  done  to 
make  a  settlement  healthy  by  planting  large  trees,  the 
eucalyptus,  etc.;  and  Martin  Clark  recommends  the  planta- 
tion of  bananas  in  the  reclamation  of  malarious  lands. 

With  regard  to  personal  hygiene,  food  should  be  taken  in 
sufficient  quantity,  and  it  is  a  inistake  to  think  that  white 
races  in  the  Tropics  can  exist  on  native  food.  They  should, 
however,  not  consume  as  much  animal  food  as  at  home. 
"Water  must  be  boiled  and  filtered,  and  milk  also  boiled. 
Coffee  apparently  acts  as  a  prophylactic  to  some  extent, 
^loderate  smoking  is  advisable.  Strict  temperance  must  be 
the  rule,  and  persons  must  protect  themselves  as  far  as 
possible  from  chill,  for  although  chill  does  not  produce 
malaria,  it  may  act  as  the  exciting  cause  of  an  attack.  The 
night  air  should  be  avoided,  because  then  the  malaria  be- 
comes concentrated,  on  account  of  the  air  cooling  more 
rapidly  than  the  earth. 

With  regard  to  the  use  of  drugs,  quinine  is  certainly 
to  some  extent  a  prophylactic,  and  should  be  taken  in  doses 
of  3  or  4  grs.  daily  during,  and  for  fourteen  days  after,  special 
exposure  in  malarious  regions ;  but  I  do  not  think  it  advisable 
to  take  the  drug  continuously,  for  in  my  experience  the 
system  becomes  habituated  to  its  use,  and,  as  it  will  not 
entirely  prevent  attacks  of  malaria,  larger  quantities  are 
required  to  cut  short  the  attacks  when  they  occur.  Another 
plan  I  have  found  successful  is  to  give  15  grs.  of  sulphate  of 
quinine  twice  a  week  for  six  weeks,  and  then  3  grs.  daily  for 
a  month.  Quinine  should  not  be  taken  in  either  tea  or 
coffee,  and  the  drug  should  not  be  given  in  the  form  of  pills. 
The  use  of  lemon  juice  is  very  beneficial,  and  arsenic  in 
minute  doses  may  likewise  be  employed  with  advantage. 

With  regard  to  the  treatment  of  malaria,  I  believe  Laveran's 
recommendation  to  be  the  best.  For  the  first  three  days 
administer  12  to  15  grs.  of  hydrochlorate  of  quinine  daily; 
from  the  4th  to  the  7th  days  omit  the  drug;  on  the  8th, 
9th,  and  10th  days  give  10  or  12  grs.  daily;  from  the  11th 
to  the  14th  days  omit  the  drug ;  on  the  15th  and  16th 
days    give   the    same    dose,    anil    again    on    the    21st    and 


Tropical  Diseases  in  Africa.  75 

22nd  days,  omitting  it  on  the  17th  to  the  20th  day.  In 
remittent  fever  the  quinine  should  be  given  when  the 
temperature  falls,  however  small  the  fall  may  be.  In 
pernicious  fevers  a  hypodermic  injection  of  the  drug  is 
indicated.  I  think  the  bisulphate  of  quinine,  with  a  little 
carbolic  acid,  and  glycerine  and  water,  at  a  temperature  of 
100°  F.,  is  the  best  solution  to  use  for  this  purpose.  In 
severe  remittent  fever  I  consider  Warburg's  Tincture  ex- 
ceedingly useful,  but  I  invariably  prescribe  it  in  the  tabloid 
form. 

Hcemoglobinuria,  or  Blach-  Water  Fever. 

This  condition  may  occur  as  a  complication  in  a  malarial 
fever,  or  it  may  occur  as  a  disease  apparently  unconnected 
with  malaria.  It  may  be  due  either  to  the  disintegration  of 
the  red  blood- corpuscles  in  the  liver  and  spleen — the  products 
being  eliminated  by  the  kidneys ;  or  the  kidneys  may  be 
congested,  and  a  dissolution  of  the  haematic  elements  in  the 
kidneys  results.  The  patient  passes  "  porter-like  urine," 
small  in  amount.  Death  is  usually  due  to  collapse  following 
suppression  of  urine,  and  there  may  be  convulsions. 

Each  case  must  be  treated  on  its  own  merits.  In  some, 
quinine  is  indicated,  dry  cupping,  and  hot  fomentations  over 
the  loins.  Diuretics  are  indicated  in  other  cases — acetate  of 
potash  with  squills.  As  Dr  Eyles  points  out,  patients 
suffering  from  this  complication  are  apt  to  be  panic-stricken. 

I  cannot  conclude  without  stating  it  to  be  my  definite 
opinion,  that  as  in  India,  so  in  Africa,  the  progress  of 
medicine  and  hygiene  will  before  long  conquer  most  of  the 
obstacles  to  the  civilisation  of  that  continent. 


76  On  the  Geographical  Distribution  of 


APPENDIX. 

A  New  Method  of  Illustratinj  the  Geographical  Distribution 
of  Diseases.  A  Paper  read  at  the  International 
Congress  of  Hygiene  aiul  Demography  at  Budapest, 
Scjyt  ember  1894. 

YoT  some  years  I  have  felt  the  want — not  alone  for  teaching, 
but  also  for  many  other  purposes — of  a  method  of  illustrating, 
clearly  and  fully,  on  a  map,  the  Geographical  Distribution  of 
Disease. 

The  methods  in  general  use — cross  etching,  shading  in 
colours,  etc,  were  at  the  best  unsatisfactory,  were  capable  of 
only  a  limited  application,  or  required  many  maps  to  illustrate 
a  district  fully. 

By  the  use  of  symbols,  as  in  the  map  which  accompanies 
this  work,  I  trust  I  have  improved  upon  these  previous 
methods.  I  have  at  least  removed  some  of  the  disadvantages 
attending  the  adoption  of  them  for  illustrative  purposes. 

Thus,  by  the  symbol  method,  not  only  can  I  show  the 
Geographical  Distribution  of  most  diseases, — even  all,  if  the 
map  is  large  enough, — but  I  can  illustrate  graphically  (by 
the  repetition  of  the  symbols)  the  degrees  of  severity  of 
disease  in  any  particular  district. 

Thus,  we  have  the  colour  and  shape  of  the  symbol,  to 
indicate  the  disease  which  is  present,  and  the  number 
(1,  2,  3)  of  symbols  grouped  together,  to  indicate  the  degree 
of  the  prevalence  of  that  disease.  For  instance,  the  Geo- 
graphical Distribution  of  Disease  in  Cape  Colony  is  in  our 
chart  illustrated  thus : — 

One  blue  dot — denoting  the  occurrence — though  to  no 
great  extent — of  Leprosy. 

Two  black  stars — denoting  the  prevalence  of  Syphilis. 

Three  red  stars — denoting  that  endemic  Ila-inaturia  is  not 
only  prevalent,  but  is  eery  prevalent. 


Tropical  Diseases  in  Africa.  77 

Again,  in  a  map  constructed  on  this  method,  a  view  may  be 
at  once  obtained  as  to  the  comparative  salubrity  of  any  area. 
Thus,  if  one  looks  at  the  Zanzibar  area,  it  is  seen  at  a 
dance  that  no  less  than  eleven  diseases  are  indicated  to  be 
very  prevalent ;  five  to  be  prevalent ;  and  only  one — Measles 
— to  be  unimportant:  we  may  therefore  conclude  that  the 
East  Coast  of  Africa  is  very  unhealthy.  Needless  to  say, 
the  nature  of  the  diseases  present  will  influence  our  opinion, 
but  enough  has  been  said  to  illustrate  the  point. 

It  may  be  well  to  point  out  here,  what  is  probably  self- 
evident,  that  for  Malaria,  the  chief  disease  of  Africa,  a  tint 
has  been  employed,  and  the  three  densities  of  colour  show 
the  intensity  of  the  malarial  process,  whilst  its  distribution 
is  at  once  obvious. 

We  admit  that  many  diseases  are  either  caused  by,  or  at 
any  rate  influenced  by,  climate,  and  therefore  I  have  intro- 
duced upon  the  map  sufficient  climatology  to  illustrate  this 
point.  The  mean  annual  temperature  is  represented  by 
figures,  thus,  80°  F.;  the  mean  annual  range  of  temperature, 
thus  (10°  r.);  the  annual  rainfall  in  inches,  50  inches; 
the  annual  relative  humidity,  70  7^;  the  annual  range  of 
humidity  (15  %);  altitude,  950  feet;  and  the  prevailiug 
winds,  by  symbols,  as  seen  on  the  map. 

A  map,  then,  constructed  upon  the  lines  1  have  thus  briefly 
laid  down,  will  at  once  give  us  the  answer  to  a  large  number 
of  questions. 

1.  What  is  the  climatology  of  an  area? 

2.  What  are  the  prevailing  diseases? 

3.  Are  these  diseases  due  to  climate  or  not? 

4.  Are  they  influenced  by  altitude  or  not? 

]\Tote. — This  last  question  may  perhaps  be  better  answered 
by  placing  my  map  alongside  one  showing  altitude,  or  by 
introducing  contour  lines  upon  it. 

Then,  if  the  area  mapped  is  a  tropical  one : — 

1.  Can  Europeans  reside  in  a  given  area? 

2.  What  precautions  should  be  taken  by  travellers,  pro- 
posing settlers,  or  armies  proceeding  there? 


78  On  the  Geographical  Distribution  of 

3.  Is  it  likely,  from  the  character  of  the  diseases  present, 
the  climatology  and  the  altitude,  that  a  given  area  may  be 
rendered  habitable  by  Europeans? 

These  problems  might  be  added  to,  but  I  have,  I  think, 
given  enough  to  illustrate  my  view,  and  I  must  be  brief. 

I  have  chosen  the  map  of  Africa  to  illustrate  my  method 
because  of  the  interest  Africa  always  excites,  and  for  this 
reason  as  well,  that  it  has  all  varieties  of  climate. 

I  have  not  overloaded  the  map  with  detail,  so  that  it  may 
the  more  clearly  illustrate  my  theory,  and  I  do  not  profess 
that  every  disease  is  represented  which  may  occur;  still, 
broadly  speaking,  it  is  correct. 

The  map  is  divided  into  areas  having,  as  nearly  as  may  be, 
the  same  climatology,  and  the  diseases  of  each  area  are 
grouped  together. 

I  will  now  take  two  or  three  of  the  questions  given  above, 
and  it  will  be  seen  how  an  answer  can  be  found  by  a  glance 
at  the  map. 

"Why  is  the  geographical  distribution  of  malaria  in  Africa 
such  as  that  represented  on  the  map  ? 

Apart  from  Northern  Africa,  malaria  is  most  severe,  as  is 
seen,  along  the  East  and  West  Tropical  coast-lines,  for  there 
heat  and  moisture  are  met  with  in  abundance,  besides  which 
the  coast-lines  are  low  and  swampy. 

Malaria  decreases  generally  as  we  leave  the  coast  and 
proceed  inland.  Why?  Because  we  have  an  increased 
altitude. 

There  is  no  malaria  in  an  area  near  Tete,  nor  in  four  areas, 
two  on  each  side  of  the  Victoria  Lake.  Why?  Because  the 
altitude — over  3000  feet — is  too  great  for  its  production. 
{Note. — This  is  a  general  statement,  local  conditions  may 
modify  it.) 

Malaria  is  generally  absent  from  the  Sahara,  because, 
though  low-lying,  there  is  little  or  no  moisture,  and  the 
heat  is  very  great.  (A  few  spots  of  malaria  are  seen ;  these 
represent  oases  where  the  disease  may  occur.) 

Altitude,  temperature,  and  probably  also  winds,  render  the 
Cape  free  from  malaria. 

Where  might  Europeans   probably  colonise   in   Tropical 


Tropical  Diseases  in  Africa.  79 

Central  Africa  ?  The  answer  is  almost  self-evident — in 
those  four  white  areas,  where  malaria  is  absent.  These 
areas,  again,  could  be  extended  by  hygienic  measures  when 
we  consider  the  configuration  of  the  country. 

Again,  looking  at  the  map,  we  find  that  with  very  few 
exceptions  (and  these  could  be  explained  by  local  conditions 
or  importations  of  the  disease)  phthisis  is  absent  where 
malaria  is  most  prevalent.  This  is  partly  explained,  no 
doubt,  by  altitude,  but  more  probably,  as  I  believe,  by  a 
certain  antagonism  between  the  two  diseases. 

This  will,  I  think,  be  enough  to  show  what  can  be  read 
with  ease  from  a  map  like  this. 

In  detailed  maps  or  smaller  areas,  of  course  much  more 
may  be  done,  and  many  more  niceties  of  detail  could  be 
introduced. 


Printed  by  M'Faklane  &  Erskine,  Edinburgh. 


Malaria, 

Typhoid  Fev 

Typhus  Feve 
Relapsing  Fe 

Cholera, 

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Diarrhoea, 

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&   S*  2    a. 


Distribution 


BY 


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Mauritius. 

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